(British-Army, Canada, US, colloquial, dated, slang) A louse (Pediculus humanus).
(Australia, Canada, US, childish, colloquial, plural-normally) Any germ or contaminant, real or imagined, especially from the opposite gender (for pre-pubescent children).
(rare) A nest-building female American coot (counterpart to cooter).
(rare, slang) A sideswiper, a type of telegraph key.
Pronounced as (IPA)
/ˈkuːti/
Etymology
Probably from Malay kutu (“flea, louse”) (and/or Tagalog/Maori). First attested in English in 1917 as British army slang during World War I.