The phrase "crooked smile" refers to a smile that is not perfectly straight or symmetrical. It can suggest someone's smile is slightly uneven or lopsided. Full definition
With a glint in his eye and that signature crooked smile, Damon sells this direct - address device beautifully — aided by Drew Goddard's warm and wickedly smart adapted script — making dialogue like «I'm going to have to science the shit out of this» into winsome laugh lines. (cbr.com)
Sarah Gadon gives one of the best performances of the year on any size screen, turning the smallest crooked smile into a major event. (rogerebert.com)
There's hints of magic peppered throughout — James Newton Howard's electrifying score, sharp visual tricks up the sleeve, Eddie Redmayne's recklessly crooked smile — but as a standalone installment, Fantastic Beasts certainly stops short living up to its titular adjective. (silverscreenriot.com)