PEEWEE
pewee, peewee, peewit, pewit, wood pewee, Contopus virens
(noun) small olive-colored woodland flycatchers of eastern North America
runt, shrimp, peewee, half-pint
(noun) disparaging terms for small people
Source: WordNet® 3.1
Etymology 1
Noun
peewee (plural peewees)
(informal) A short or small person; a small object.
A kind of small marble in children's games.
(US, sports) A player in a sports league for very young children.
Etymology 2
Probably from onomatopoeia of the birds' songs.
Noun
peewee (plural peewees)
(Australia, New South Wales and Queensland) A magpie-lark or mudlark, Grallina cyanoleuca.
A pewee.
Source: Wiktionary