(noun) - (1) A term of reproach, the meaning of which appears to be unknown to those who use it. It is evidently a corruption of whore's-bird, to which it must be added that bird in Old English and Anglo-Saxon means birth, and hence offspring, progeny; or the Old English burd, bride, young woman, in which case the term means a bastard daughter. Either way, it comes to much the same, and the term was easily generalized.
--William Cope's Glossary of Hampshire Words and Phrases, 1883
(2) Whore is the past participle of Anglo-Saxon hynan, to hire. The word means simply someone, anyone, hired. It was formerly written without the w.
--John Tooke's Diversions of Purley, 1840
(3) Wasbird, a wartime phrase used of any elderly man eager to enlist.
--Edward Fraser's Soldier and Sailor Words and Phrases, 1925
(4) Used also of children and occasionally of animals.
--Joseph Wright's English Dialect Dictionary, 1898-1905