Ratchet (noun)

A mechanical device consisting of a rotating cog with teeth that engage a pawl and permit movement in only one direction, often used to tighten or secure an object.

Origin:

From the french word rochet, meaning 'little wheel'.

Examples:

1. The mechanic used a ratchet to tighten the bolts on the engine block.
2. A ratchet is a useful tool for tightening bolts in tight spaces.
3. The ratchet made a clicking sound as he tightened the bolts.
4. A ratchet is often used in conjunction with a socket to turn nuts or bolts.
5. Ratchets are commonly found in automotive and mechanical workshops.