Definitiondefecation, a nursery term, the usage of which has extends into adult life. See defecation for synonyms.
(1) Lionel Twain (Truman Capote), claiming to be the greatest detective, and Sam Diamond (Peter Falk) contradicting him in Murder by Death (1976):
-- Lionel: ' Look at me! I'm the greatest! I'm number one! '
-- Sam: ' To me you look like number two. Know what I mean? '
(3) Penguin/Oswald Cobblepot (Danny De Vito) because his parents threw in the sewers as a child in Batman Returns (1992): ' I was their number one son and they treated me like number two.'