Scottish National Dictionary (1700–)
1. A bow in salutation. Gen.Sc. [bu:]
Sc.  R. Chambers Pop. Rhymes (1870) 124:
There's a beck, and there's a boo, Open your gates and let us go through. Ork.(D) 1880 Dennison Orcad. Sk. Bk. 13:
He aff wi' his muckle hat, an' meed a boo tae her.
2. An arch; a bend or curve.
Abd. 1920 Anon. Gleanings Deeside Par. II. 5:
The boo o' the Brig o' Dee's biggit wi' bricks. Bch. 1928 (per Abd.15):
There wis some boos in 's furrs.
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"Boo n.3". Dictionary of the Scots Language. 2004. Scottish Language Dictionaries Ltd. Accessed 23 Mar 2018 <http://www.dsl.ac.uk/entry/snd/boo_n3>
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