Main Entry: 1im·ple·ment
Etymology: Middle English, from Late Latin implementum action of filling up, from Latin implEre to fill up, from in- + plEre to fill -- more at FULL
1 : an article serving to equip <the implements of religious worship>
2 : a device used in the performance of a task : TOOL, UTENSIL
3 : one that serves as an instrument or tool <the partnership agreement does not seem to be a very potent implement -- H. B. Hoffman>
A crochet hook is an implement. You need to call the manager is a cashier told you otherwise.