ONlwSG

piorradh m. [ˈpʰjuɍəɣ], gen. piorraidh [ˈpʰjuɍi], ‘squall, blast’. MacBain (1911) derives piorradh from late MEng. pirry ‘a whirlwind, blast’ (Eng. pirrie); MacLennan (1925) derives it from Scots pirr ‘a gentle breeze’; and Stewart (2004, 411) from ON byrr m. ‘a favourable wind, wind for sailing (NO)’, although McDonald (2009, 348) considers this uncertain.

Piorradh also has the sense ‘stab or dash at something’ and is the verbal noun of piorr (piòrr 

Lengthening developing in more northerly and westerly dialects.

) vb. SG piorradh and piorr (piòrr) are possibly from Scots birr ‘a strong, sudden breeze; force, energy, enthusiasm, bustling activity; passion, angry excitement etc.’ (itself from ON byrr) and the denominative verb birr ‘to commence to blow; sail before a fair wind; move rapidly or energetically etc.’ (SND^˄, s.v. ¹birr, bir), respectively, with p- for initial b-, perhaps conflated with the onomatopoeic variants pirr, †pirrhe (MScots pir, pirhe) ‘a gentle breeze; sudden excess of activity etc.’ and pirr ‘to ripple, stream; bowl or whirr along; blow gently; tremble with anger’ (ibid., s.v. ²pirr).

?Cf. Ir. biorrughadh ‘act of budding, reviving, becoming active’ (Dinneen 1947), biorú ‘replenishing, springing, recovering’ (Ó Dónaill 1977, s.v. bioraigh).

There may also be conflation with SG purr (pùrr) ‘to stab, thrust, push, jostle’ (verbal noun purradh), from Scots porr ‘to thrust, poke’. Moreover, piorr (piòrr) also has the sense ‘to scrape, dig’, 

Cf. Mac-Dhonuill 1751, 33: le piorradh na ’n íngnin [le piorradh nan ìnean].

but this is probably from Scots pare ‘to pare, scrape, scarify’ (MacBain ibid.).

The early written forms of this word are piorra (Shaw 1780; Armstrong 1825) and piorradh (Armstrong; HSS 1828). This is reflected in /pjuRəɣ/ (AFB^˄), but contrast (Islay) [pėúr´-Ă] (i.e. ?/pjurəɣ/ not /pjurːəɣ/) (M^cAlpine 1832, s.v. piorradh) and (Glengarry) [pirəG] (i.e. /pirəɣ/ not /piRəɣ/) (Dieckhoff 1932, s.v. piorr), which might be written *pioradh, with lenited r. It may be that a conflation of the Scots verbs and substantives birr [bɪ̢̈r, bʌr] and pirr, under the influence of the spelling forms Scots †pirrhe (MScots pirhe) and/or Eng. pirrie, were borrowed contemporaneously in Argyllshire and Central Scotland 

Cf. (Argyllshire) MacDougall 1891, 86, 122: piorradh de ghaoith near ‘a sudden blast of east wind’; Deo-Ghréine XII, 1916, Earrann 3, p. 35, and XIII, 1918, Earrann 10, p. 146: piorradh-gaoithe; also (Cape Breton, but origin uncertain) Mac-Talla VIII, 1899, No. 18, p. 1: piorradh.

as *pior and *piora (*pioradh, with a closing fricative in Gaelic) (e.g. (Glengarry) [pir·], [pirəG]), but by association spelt piorr and piorra (piorradh), which in turn have since yielded the spelling pronunciations /pjuːR/ and /pjuRəɣ/ (AFB^˄, s.v. piorr, piorradh), respectively. Later, the diminutive Scots pirrie (SND^˄, ²pirr) was itself borrowed as SG piorraidh.

MacLeòid 1923, 68: le piorraidh [‘in a fit of temper’].