v1.0
Published 01/10/24
trìlleachan m. [ˈt̪ɾiːʎ̪əxan], axan], ɔxan], gen. trìlleachain -[æɲ], -[ɛɲ], ‘a wading bird, (frequently) oystercatcher, Haematopus ostralegus, (less commonly) sanderling, Calidris alba, sandpiper, Actitis hypoleucos, or ringed or grey plover, Charadrius hiaticula, (occasionally) dunlin, Calidris Alpina, turnstone, Arenaria Interpres, or sand plover, Charadrius mongulus’, often with a qualifying specific noun or adjective (see below).
Goodrich-Freer (1897, 67) cites an otherwise unattested SG trill, which she relates to ON troll ‘evil spirit’ and trylla ‘to enchant’, with reference to the bird’s mournful cry. Henderson (1910, 128: trilleachan, drilleachan) suggests a connection with ‘Norse’ trítill m. ‘a top’ and trílla vb. ‘to trot at a slow pace’, but these are modern Icelandic words related to Dan. trilde (Cleasby 1874). Henderson also cites Cleasby’s Ice. trýtill m. (sic) ‘a bird’, from Íslenskar Þjóðsögur II, cf. the fairy story ‘Karlssonar, Lítill, Trítill og Fuglarnir’ (‘Karlson, Lítill, Trítill and the birds’), in which Lítill and Trítill are in fact the names of elves, not birds (Árnason 1864, 446–49). McDonald (2009, 423–44; 2015, 130–31) considers the loan uncertain. A variety of Scottish Gaelic forms are found: 
In the following, unless otherwise indicated, the oystercatcher is being referred to.
A. With initial t-.
A 1. SG trìlleachan [ˈt̪ɾiːʎ̪əxan], axan], ɔxan]
(i) trìlleachan (MacBain 1911; Faclan bhon t-Sluagh˄: South Uist or Skye, [t̪ɾı:lʹɑxɑṉ] Lewis (with /ʟ´/); Garvie 1999, 61; Cox 2002a, 354: gen. in Rubha an Trìlleachain [ʀu ə ˈɴthri:ʟ´ɔxan] ‘the promontory of the oystercatcher’ NB2145). AFB˄ (/triːLʲəxan/) defines the word as an ‘unspecific term for a noisy sea-bird (esp. oystercatcher, sandpiper, guillemot or grey plover)’. In open compounds, with a following specific adjective or (genitive) noun: (tràigh f. ‘shore’) trìlleachan-tràghad (AFB˄), trìlleachan-tràighe (Garvie; AFB˄: ‘ringed plover’); (beag adj. ‘small’) trìlleachan-beag ‘turnstone’ and (glas adj. ‘grey’) trìlleachan-glas ‘sanderling’ (Garvie; AFB˄).
In the preceding, Garvie omits hyphens, leaving a space.
(ii) trilleachan, with the lengthmark omitted (Henderson 1910, 128; MacLennan 1925: [treeliuchan]; Lockwood 1971, 28–29; 1984, 158; Faclan bhon t-Sluagh˄: Scalpay); in open compounds: trilleachan traighe (Mac Farlan 1795), trilleachan-traighe (Forbes 1905, 37, 318: oystercatcher, 37: ringed plover). For South Uist, Faclan bhon t-Sluagh˄ defines trilleachan as a ‘small bird with shrill voice, found on sand beaches’, cf. trilleachan ‘grey plover’ (Armstrong 1825; Forbes 1905, 321: plover), ‘sanderling’ (Lockwood 1984, 158; Forbes 1905, 37: trilleachan-glas) and ‘sandpiper’ (Forbes 1905, 37: trilleach-an-traghaid (sic), trilleach-an-traighich (sic), 331: trilleachan, trilleachan-traghaid, trilleachan-traighich; Lockwood 1984, 158: trilleachan; Faclan bhon t-Sluagh˄: idem, Argyll).
The second edition of GOC (Gaelic Orthographic Conventions) advocates the spelling trilleachan, as opposed to trìlleachan, misconstruing (or misapplying) the rule whereby the stressed vowel preceding an original geminate is long in monosyllables but short in polysyllables when immediately followed by a vowel, e.g. (long) till vb ‘to return’, (short) tilleadh m. ‘returning’ (Cox 2010a, 166–67; 2017, 13 fn 29).
The word is further mispelt trillachan traighe in Shaw 1780, and, presumably due to a copying or typesetting error, trigleachan in Forbes 1905, 37, 321.
(iii) trill: Goodrich-Freer (1897, 67–68) cites trill ‘sand plover’, but we should probably read trìlleachan, which may have been truncated by association with ON troll and/or trylla, to which Goodrich-Freer proposes a connection (see above).
(iv) trìleachan: this form is given in HSS 1828, as an alternative to trìlleachan in MacBain 1911, and in error for trìlleachan in Faclan bhon t-Sluagh˄ ([t̪ɾi:lʹɑxɑṉ] Harris, with /ʟ´/); cf. trìleachan tràghad (HSS); cf. trilichan (Martin 1698, 109), without lengthmark. The form trìleachan, with a lenited palatal lateral, appears to be supported by SG trilean (sic) m. ‘trill’ and trileanta (sic) adj. ‘trilling, trilled’ (cf. Armstrong 1825; Dwelly 1911; AFB˄). HSS (1828) also lists trileanta, citing Alasdair Mac Mhaighstir Alasdair; in fact the latter (Mac-Dhonuill 1751) gives (p. 39) (len.) thriolonta and (p. 22) trileonta (so Shaw 1780). In his own edition of Mac Mhaighstir Alasdair’s poems, Thomson (1996b, p. 85 line 751: thrileanta, and p. 91) notes of the first instance that ‘[t]he i of trileanta should perhaps be long, if the word is connected with Older Gaelic trírech, trílech’; of the second, Thomson (p. 67 line 479: trileanta) makes no comment, and yet, given that trileanta forms an aicill-rhyme with mion-dhìonach (1751: mindhíonach), we should probably read trìleanta and, consequently, the subsequent forms trilean and trileanta are probably incorrect.
Cf. Thomson ibid.:
Ochòin! a feadan bailleagach,
Cruaidh, sgailleagach, glan, ceòlmhor,
Nam binn-phort stuirteil, trileanta,
Rèidh, mion-dhìonach, bog, rò-chaoin
(with end-rhyme between lines b and d, and with aicill-rhyme between a and b, and between c and d).
(v) trileachan (Forbes 1905, 37, 318: oystercatcher, 37: ringed plover); in open compounds: trileachan-glas (Fergusson 1886, 66: sanderling), trileachan-traighe (ibid.: turnstone, sandpiper, ringed plover), with the lengthmark omitted (see (iv), above).
(vi) trìleach: Alexander Carmichael (CG VI, 141) lists the entry trìleach 
Spelt trìlleach in CG III, 260: ‘Cha robh fios fo’n ghréin ghil ’d è theirte na dhèante anns an trìlleach [sic] a bh’ann’ (no one had the least idea what to say or do in the ensuing confusion).
‘trouble, fight, squabble’, followed by the entry trìlleach ‘in winter; gulmag [‘ringed plover’] in summer. The bird changes its colour in summer’: for trìlleach (the bird) we should probably read trìlleachan, which may have been truncated in error following the entry for trìleach.
(vii) triollachan: Alasdair Mac Mhaighstir Alasdair (MacDomhnuill 1741, 76) lists triollachan ‘grey plover’; this may be for trìollachan, with an unlenited non-palatal lateral, but, considering Mac Mhaighstir Alasdair’s triolonta, trileonta for trìleanta (see (iv), above), perhaps trìleachan. In spite of similar forms in Shaw (1780: triollachan ‘grey plover’), Armstrong (1825: triollachan ‘grey plover’, triollachan traighe ‘oystercatcher’), Ross (c.1890: triolachan, St Kilda), Forbes (1905, 321: triollachan ‘plover’) and Lockwood (1984, 158: triollachan ‘oystercatcher, sandpiper, sanderling’) – most of which probably go back to Mac Mhaighstir Alasdair – independent evidence for trìollachan, as opposed to trìl(l)eachan, seems lacking.
A 2. SG trìlleachdan [ˈt̪ɾiːʎ̪əxkan], axkan], ɔxkan]
With final -achdan, cf. aonrachan m. ‘hermit’ > aonrachdan:
(i) trìlleachdan (McDonald 1972, s.v. trinnleachdan: Barra), and
(ii) trinnleachdan (ibid.: a shore bird (e.g. dunlin, sanderling, ringed plover), South Uist), with a long, nasalised stressed vowel.
B. With initial d-, cf. treis f. ‘while’ > dreis (Cox 2017, 381 fn 11)
B 1. SG drìlleachan [ˈd̪̥ɾiːʎ̪əxan], axan], ɔxan]
(i) drìlleachan (Cunningham 1990, 227), cf. drìlleachan ‘sandpiper’ (MacLennan 1925: [dree-luchan]); in open compounds: drìlleachan beag (Garvie 1999, 61: turnstone);
(ii) drilleachan (Henderson 1910, 128; Cunningham 1990, 92; Forbes 1905, 26, 318), with the lengthmark omitted; in open compounds: drilleachan-traghad (Forbes ibid.); cf. drilleachan ‘sandpiper’ (McAlpine 1832: [drēlly´-ach-an]), ‘sanderling’ (Faclan bhon t-Sluagh˄: Tiree).
B 2. SG drìlleachdan [ˈd̪̥ɾiːʎ̪əxkan], axkan], ɔxkan]
drìlleachdan (McDonald 1972, s.v. trinnleachdan: Barra), cf. A 2.
(Lockwood (1971, 28) compares Ir. trilleachán trágha ‘oyster-picker’, listed by Dinneen (1947), who cites O’Reilly’s (1817; 1864) Irish dictionary, which gives trilleachan-traighe ‘gatherer of oysters’ and triollachán ‘grey plover’, both from Shaw’s (1780) Scottish Gaelic dictionary: trillachan traighe ‘collared oyster-catcher’ and triollachan ‘grey plover’.)
EG trílech ‘trilling of birds etc.’ (eDIL˄, s.v. trírech) yields SG trìleach regularly (cf. SG trìlean and trìleanta), hence the derivative SG trìleachan ‘something that trills’, with the Gaelic suffix -an, and the by-forms trìlleachan, trìlleachdan, trinnleachdan, drìlleachan and drìlleachdan; whether the latter ever included a form or forms with a non-palatal lateral (e.g. trìollachan) is uncertain.
Cox 2002a, 354; cf. Lockwood 1971, 28–29; 1984, 158. For a proposed connection between SG trìleach ‘trouble etc.’ and EG trílech, see CG VI, 141, and Matheson 1938, 374. Vendryes (1996) sees an onomatopoeic origin to EG trírech, trílech, and compares Gr. τρίλω and Pokorny 1959, 1036, s.v. *(s)treig-. Ir. roilleach and roilleog ‘oyster-catcher’ (Dinneen 1947) go back to EG ruilech ‘idem’ (eDIL˄) and are unconnected with EG trírech, trílech.