Publishing history:v1.0
v1.0: 01/11/24
meilearach f. 
Cf. a’ mhilearach (Tobar an Dualchais ID61185, @ approx. 2.14–2.25 mins, Barra 1976), and Ir. miléarach f., below; however, MacLennan (1925) and AFB˄ give SG meilearach as masculine.
[ˈmẽlaɾəx], -[ax], -[ɔx] 
While MacLennan (1925: [melurich]) and AFB˄ (/melərəx/) give forms with medial [ə] (see below), derivation from a compound in final fheurach (see below) would be expected to yield medial [a], cf. (lenited after the article) [vĩlaɾʌx], (dat.) [vĩlaɾiç] (Tobar an Dualchais ibid., Barra 1976) and ?[mĩlarɔx] (ibid. ID15737, @ approx. 6.21 mins, Benbecula 1998).
in the sense ‘long sea-side grass’ is derived by MacBain (1896; 1911) from ON melr m. ‘bent-grass’; so also Henderson (1910, 215), MacLennan (1925), Stewart (2004, 411) and McDonald (2009, 386). However, ON melr nom. would formally yield SG *mealr *[ˈmjɑ̃ɫ̪͡ɑɾ]; ON mel acc. would formally yield *meal *[mjɑ̃ɫ̪].
Final -r of ON melr is the nominative singular ending and not part of the stem.
For meilearach, cf. SG miolarach (McDonald 1972, s.v. milfhiarach: South Uist and Eriskay), both of which appear to go back to milfheurach, a closed compound of SG mil ‘honey’, here used adjectivally in the sense ‘sweet’, + (len.) feurach ‘pasture’, from SG feur ‘grass’ + the suffix -ach (with a locational function (Cox 2002a, 60)); cf. Ir. miléarach ‘grass wrack, eelgrass’ (Ó Dónaill 1977).
Cf. Ir. mil-fhéarach (Dinneen 1947). McDonald (2009, 386) gives Ir. mílearach in error. SG meilearach etc. is distinct from SG mìnear, mìn-fheur ‘fine, smooth or soft grass’ < SG mìn ‘fine’ + feur (e.g. MacLennan 1925 and Dieckhoff 1932).
It may be, of course, that SG milfheurach and Ir. miléarach represent folk-etymological reflexes of forms in SG/Ir. muir- ‘sea’, cf. SG muran and Ir. muiríneach ‘marram grass’, also Dwelly’s (1911, s.v. meilearach) cross-reference to SG muirineach, all probably derivatives of muir ‘sea’ (MacBain 1911, s.v. muran; eDIL˄, s.v. muirin, muirnech). There is also the possibility of conflation with derivatives of EG bilar ‘the name of a water plant’ (eDIL˄), 
Earlier birar (< bir ‘water’ + the collective suffix -ar (Vendryes 1996)). The dissimilation in birar > bilar may have been at least partly motivated by analogy with EG bile ‘tree’, bileóc ‘leaf’.
viz. SG bilearach, bileanach 
With dissimilation of r > n.
(dial. bileineach) ‘sweet seagrass’ (Dwelly 1911) and milear 
For b- > m-, see Ó Maolalaigh 2003, 128.
‘marram (grass)’ (AFB˄: /milər/). Further, compare AFB˄’s meilearach /melərəx/ ‘marram (grass)’ (with medial /ə/) with AFB˄’s bilearach /bilərəx/ ‘(marine) eelgrass’.
With medial [ə] commensurate with the short vowel of the collective suffix -ar.
Dwelly (1911: meilearach) gives the senses ‘sea-maram, sea-matweed’, AFB˄ (idem /melərəx/, Eriskay) the senses ‘marram (grass), European marram grass/beachgrass (Ammophila arenaria)’, and Faclan bhon t-Sluagh˄ (milarach [sic], Harris) ‘tender, sappy grass on the bed of the ocean’ and (milearach) ‘eelgrass’, while McDonald (1972, s.v. milfhiarach: South Uist) gives the sense ‘sea-grass out of which beds are made’. (Note that AFB˄’s meilearach is associated with Eriskay on the basis that the form meallthìreach ‘submerged roots found in dry peaty soil especially in embankments ... used to make ropes’, recorded in Eriskay (Faclan bhon t-Sluagh˄, s.v.), is the same word as Dwelly’s (1911) meilearach ‘sea-maram, sea-matweed’ (pers. comm. AFB’s editor Michael Bauer), but s.v. millteach.)
See also under mealbhach and mealbhan, meallach and millteach.