DSL - SND1 U, letter of the alphabet . The twenty-first letter of the alphabet , now called [ju] as in Eng., but earlier [u], written uh, oo (Sc. 1721 Ramsay (S.T.S.) Gl. s.v. Woo; Crm. 1854 H. Miller Schools ii.; Bnff. 1874 W. Gregor Olden Time 39; Sh. 1958 New Shetlander No. 46. 24). See also [W], letter .
1. It has several sounds in Sc.: (1) that of the high back tense rounded vowel [u], written variously u, oo, ou, ow, ew, ue, which in the wm.Sc. area especially tends to be markedly advanced in the direction of [y], e.g. Boo, drew, [DU], pron., [FOU], [MOU], [POU], true. The distinction in length and tenseness in Eng. between the u sound in food, moon, rude [u(w)] and that in cook, foot, full, good, pull, push, put, stood [u] is not made in Sc. Before -r a glide gen. develops in Sc. as [FLOUR] [flur], [SOUR] [sur], poor. The sound  may be said to have disappeared from mainland Sc., exc. for an obsol. survival in Rxb., where the sound  freq. written uo, developed from O.Sc. Q as in bonnie, coal, folk, frost, morn, rose, storm, etc. See [O], letter , 1., Murray D.S.C.S. 111, 147, Watson W.-B. § 71, P.L.D. § 105), as also in Cmb. dial. In Sh. an almost identical sound, for which Jakobsen uses the symbol [⊙], is characterised in this dictionary by  and gen. written by Sh. authors with u, as [KUL], [LURT], [MUN], v., [RUNK], v.1, [SKULP], [SKUTTEL], [STRUBBA]; (2) that of the high back lax rounded vowel , as in [BUCHT], cut, dumb, [GUDDLE], [HURL], [LUNT], [PUTT], [RUNG], turn, work, etc., tending also to  in unstressed syllables, as [ELBUCK], [STOLUM]. In the neg. pref. [UN-] and in [UP], the earlier pronunciations [un-, up] are occas. heard, though nearly obs.; (3) when followed by a consonant and a mute e, it frequently indicates the sound [ø, y, I]. See 2. (4).
2. u appears in various digraphs: (1) au, representing the sound [Q:], in em. and wm. Sc. and gen. adopted as the standard spelling in other dialects also, where the vowel remains unrounded, exc. Sh. where the spelling aa is preferred. Hence
[CAULD], [DRAUCHT], [HAUCH], [HAUD], [LAUCH], [MAUN], [SAUT], [WAUR]. See P.L.D. §§ 48, 85, 93, and [A], letter , II.; (2) eu, (i) for [ju], as in [FEU]; alternating with [(j)] according to dialect, in words orig. with O. and Mid.Eng. &omacrdotbl; before ch [x] or k, as [BEUK], [DEUK], [ENEUCH], [HEUCH], leuch ( [LAUCH]), [LEUK], [PLEUCH], [TEUCH]. See P.L.D. § 35.6.; (ii) for [ø] esp. in Ork. writing from Dennison onwards, as geud ( [GUID]), creuk ( [CRUIK]), deud ( [DAE]), meun ( [MUNE]), seut ( [SUIT]), peur ( [PUIR]). See (4) below; (3) ou, (i) for [u], (ii) for [u]. See [O], letter , 2. (2), 3. (4); (4) ui, (i) for [ø, y, later unrounded to I], alternating with the earlier u-e, which is now usu. retained only before nasals, as in [BRUME], dune ( [DAE]), [LUME], [MUNE], [SPUNE], [TUME]. [TUNE], etc., also [BLUDE], [SCHULE], and representing O.E. , O.N. ó, O.Fr. u (see P.L.D. §§ 20, 35), as in [BUIT], n.1, [CUIL], [FUIL], [GUID], [HUILIE], [MUIR], [PUIR], [SHUIR], [TUIL], [WUID]. See Burns Intro. to Gl. to 1787 edition. This spelling has become a literary standard also in n.Sc. where the actual pronunciation is [i]. See also [O], letter , 3. (3) (ii); (ii) for [e] from the same etym. sources, when in final position and before r and the voiced fricatives v, z, in m.Sc., and, more gen. for (i) in Ags., Fif. Hence [DAE], [SHAE], [TAE], prep., adv., flair ( [FLUIR]), pair ( [PUIR]), shair ( [SHUIR]); [EXCAISE], maisic ( [MUSIC]), refaise ( [REFUISE]), yaize ( [USE], v.). The spelling of u for &omacrdotbl;, due chiefly to the influence of French spelling, originates in North.Mid.Eng. in the mid 14th c. and is found in Scottish MSS. from about the same time. The i represents length of vowel as in ai, ei and (in O.Sc.) oi.
3. u is not kept distinct in spelling from v and w in O.Sc. and this practice survived into the early 18th c., e.g. tua (
[TWA]), tuell ( [TWAL]), Twesday, urett, wrote (Sc. 1700 W. Fraser Scotts of Buccleuch (1878) II. 374), uryt, write (Sc. 1701 Rec. Conv. Burghs 440, 1716 W. Fraser Sutherland Bk. (1892) II. 215).
4. (1) u [u], with its variant spellings, originates (i) chiefly in O.E. , O.N. ú, O.Fr. ou. See P.L.D. §§ 38-40, note also § 101; (ii) in O.E. l and O.N. úl final, ul- before a consonant, where the l is vocalised. See P.L.D. §§ 60.2, 78.3.,
[L], letter , 1.; (iii) also from wi after s, as in [SOOM], v.1, [SOOP], soord ( [SWURD]). See P.L.D. § 76; (2) u  goes back (i) mainly to O.E., O.N. u and , ú, O.Fr. u, ou with later shortening (see P.L.D. § 60 and cf. [BUN], ppl.adj.1, fund ( [FIND]), [GRUND], [HUND]; [FUNTAIN], [MUNTAIN]; bushel, [PUSH]; (ii) to O.E., O.N. i in proximity to a labial consonant or a velar l or both, as burd, bird, but, bit (Sc. 1752 Lyon in Mourning (S.H.S.) III. 128), fussle ( [FISSLE]), hum, him (Fif. 1845 Stat. Acc.2 IX. 42), wull ( [WILL]), wut ( [WIT]), whun ( [WHIN]), whusky, whuskers, whustle, mulk ( [MILK]), [MUCKLE], puckle ( [PICKLE]). Cf. also sullie ( [SILLY]). See P.L.D. § 59. This feature is extended to many other collocations with i with varying degrees of thoroughness in the various dialects. It is particularly frequent in Ork. and Arg. (see P.L.D. § 95.2. (1) and N. Munro Para Handy passim) and in Per. (see Wilson L. Strathearn 40-1). Cf. also [CHUCKEN], durty (Inv. 1741 Trans. Gael. Soc. Inv. XIV. 274), shurt ( [SHIRT]), shunner ( [SHINNER]), [STUDDIE]. Conversely u appears as [I] in e.g. bibble ( [BUBBLE]), tribble, [TROUBLE] (cf. Burns To a Mouse vi.), [RIBBLE]; (iii) to o in buddy ( [BODY]), in [DUG], [MONIE], in some areas of m. and s.Sc., [TRODGE]; (iv) in [BULL] and [FULL] [fl], [PULL] [pl], as variants of [FOU], [POU]. See [L], letter , 1. (1).