n.1. A tight curl, twist, or bend in a length of thin material, as one caused by the tensing of a looped section of wire.
2. A painful muscle spasm, as in the neck or back; a crick.
3. A difficulty or flaw that is likely to impede operation, as in a plan or system.
4. A mental peculiarity; a quirk.
5. An unusual or eccentric idea.
6. Slang Peculiarity or deviation in sexual behavior or taste.