kink

a painful muscle spasm especially in the neck or back (`rick' and `wrick' are British)

a sharp bend in a line produced when a line having a loop is pulled tight

a person with unusual sexual tastes

an eccentric idea

a difficulty or flaw in a plan or operation; "there are still a few kinks to iron out"

curl tightly; "crimp hair"

form a curl, curve, or kink; "the cigar smoke curled up at the ceiling"