take (one) for a fool

take (one) for a fool

To presume or believe that one is very stupid or foolish. I'd advise you not to take her for a fool. She may play dumb, but she's very crafty.
See also: fool, take
Farlex Dictionary of Idioms.

take someone for an idiot and take someone for a fool

to assume that someone is stupid. I wouldn't do anything like that! Do you take me for an idiot? I don't take you for a fool. I think you're very clever.
See also: and, fool, idiot, take
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • take for an idiot and take for a fool
  • take (one) for an idiot
  • play (one) for a fool
  • play for a fool
  • play someone for a fool
  • take for
  • doofus
  • knuckleheaded
  • a right one
  • fool and his money are soon parted