lid

1. (slang) A cap or hat.Examples: "“Yes, sir, if that was the language of love, I'll eat my hat,” said the blood relation, alluding, I took it, to the beastly straw contraption in which she does her gardening, concerning which I can only say that it is almost as foul as Uncle Tom's Sherlock Holmes deerstalker, which has frightened more crows than any other lid in Worcestershire."slang

2. (slang) One ounce of cannabis.slang

3. (surfing, slang, chiefly Australia) A bodyboard or bodyboarder.Examples: "Mal rider, shortboard or lid everyone surfs like a kook sometimes."; "the rest of us managed to dodge out of control lid riders"Australiaslang

4. (biology) An operculum or other lid-like cover.

5. (slang) A motorcyclist's crash helmet.slang

6. (slang) In amateur radio, an incompetent operator.slang