Definition of I she, etc. wasn't born yesterday in English:

I (she, etc.) wasn't born yesterday

Used to remind someone that one isn’t naive.
More example sentences
  • I may sell Bibles but I know which end is up and I wasn't born yesterday and I know where I'm going!
  • Listen, I wasn't born yesterday… you think that if you're nice to Jeremy he'll open up to you and that's when you strike in for the kill.
  • Now Pet, you of all people know I wasn't born yesterday.
See parent entry: born

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Word of the day dinkum
Pronunciation: ˈdɪŋkəm
adjective
(of an article or person) genuine, honest, true