Answer:

squarepeg

Answer	Crossword Clue
SQUAREPEG	Part of a bad fit
SQUAREPEG	Figurative misfit, with
SQUAREPEG	Apt username for Margaret, the geometry teacher?

SQUAREPEG	Part of a poor match, maybe
SQUAREPEG	Misfit.
SQUAREPEG	Misfit, in a saying
SQUAREPEG	Potential misfit
SQUAREPEG	Something that's hardly fitting?
SQUAREPEG	Misfit