someone who is different from most people of the same age and situation.
In high school she was defininitely a square peg, but even if they didn't understand her, most kids admired her.
square peg
One who acts or thinks differently than most people. Typically used in the phrase "a square peg in a round hole." The young girl who had a love of math and science often felt like a square peg in a round hole when surrounded by her peers.When the man in the fancy suit walked into the biker bar, it was obvious that he was a square peg.