A woman, especially an old woman; especially one regarded as fussy or mean or a gossipy busybody.
An attractive girl.
An Irish maidservant.
(by extension) An Irishwoman.
A name used in calling a hen or chicken, often as "biddy-biddy-biddy".
(often in the plural) bitch, girl, woman, especially one that is promiscuous
He's got it made, hanging around with the bitties all the time.