bonnet

1. (by extension) The polishing head of a power buffer, often made of wool.Examples: "Make sure that the power buffer's lamb's-wool bonnet is clean. Change or rinse the bonnet frequently to avoid scratching the finish. Use the bonnet as a mitten to buff in the crevices and other areas that the power buffer can't reach."broadly

2. (Australia, British, New Zealand, South Africa, Commonwealth, automotive) The hinged cover over the engine of a motor car, also known as a hood in chiefly Canada and the US.Examples: "The car is burgundy red, wide and elegant, ten years old but still the boys are impressed and they run to touch it, pressing sticky handprints against the polished bodywork and trying to climb up onto the bonnet."; "People were reluctant to slam a bonnet shut in those days. One just did not slam bonnets and doors."; "By about 20 ms, there is contact between the bonnet leading edge and the pedestrian upper leg/pelvis on the struck side, the severity of which depends on the vehicle shape."Synonyms: hoodAustraliaBritishCommonwealthNew-ZealandSouth-Africa

3. (nautical) A length of canvas attached to a fore-and-aft sail to increase the pulling power.Examples: "And standing along to the Westward, this night we tryed with our mayne coarse and bonnet. On Saturday night we came to an anker, in three fathomes against Sewramo."

4. (obsolete, slang) An accomplice of a gambler, auctioneer, etc., who entices others to bet or to bid.obsoleteslang

5. (historical) A ducat, an old Scottish coin worth 40 shillings.historical

6. Anything resembling a bonnet (hat) in shape or use.