hat

Old English hæt "hat, head covering," from Proto-Germanic *hattuz "hood, cowl" (cf. Frisian hat, Old Norse hattr), from PIE root *kadh- "cover, protect" (cf. Lithuanian kudas "tuft or crest of a bird," Latin cassis "helmet"). Now, "head covering with a more or less horizontal brim." To throw one's hat in the ring was originally (1847) to take up a challenge in prize-fighting. To eat one's hat is said to have been originally To eat Old Rowley's [Charles II's] hat.

Ask for financial contributions, as in Let's pass the hat so we can get her a nice going-away gift. This expression alludes to the actual practice of passing a hat around a gathering, but it is also used more figuratively, as in The board decided to pass the hat again among the corporate sponsors. [Late 1800s]

In addition to the idioms beginning with hat

• hate someone's guts
• hat in hand
• hat in the ring
• hats off to
• hat trick

also see:

• at the drop of a hat
• brass hat
• eat one's hat
• hang on to your hat
• hang up (one's hat)
• hard hat
• hats off to
• keep under one's hat
• knock into a cocked hat
• pass the hat
• pull out of a hat
• take one's hat off to
• talk through one's hat
• throw one's hat in the ring
• wear another hat

Also see undercap.