crimper

transitive verb

1. to press into narrow, regular folds; pleat or corrugate
2. to make (hair, etc.) wavy or curly
3. to gash (the flesh of a fish, etc.) so as to make the muscles contract and stay firm in cooking
4. to mold or bend (leather for shoe uppers, etc.) into shape
5. to pinch together or fold the edge of (one part) tightly over another
6. ☆ Informal to obstruct or hamper

noun

1. the act of crimping
2. a crimped pleat, fold, or part
3. ☆ crimped hair
4. ☆ wavy condition; esp., the natural waviness of wool fiber