"characterized by odd fancies, eccentric in thought," 1825, from crotchet "whim or fancy" + -y (2). Related: Crotchetiness. *Crotchetily seems little used, but it is an ugly word.
cross-wind
crosswise
crossword
crotch
crotchet
crotchety
crouch
croup
croupier
crouton
Crow