n. & v.
--n.
1. a a short thick terminal projection on the human hand, set lower and apart from the other four and opposable to them. b a digit of other animals corresponding to this.
2 part of a glove etc. for a thumb.
--v.
1. tr. wear or soil (pages etc.) with a thumb (a well-thumbed book).
2 intr. turn over pages with or as with a thumb (thumbed through the directory).
3 tr. request or obtain (a lift in a passing vehicle) by signalling with a raised thumb.
4 tr. use the thumb in a gesture.
Phrases and idioms:
be all thumbs be clumsy with one's hands. thumb index n. a set of lettered grooves cut down the side of a diary, dictionary, etc. for easy reference.
--v.tr. provide (a book etc.) with these. thumb one's nose cock a snook (see SNOOK(1)). thumb-nut a nut shaped for turning with the thumb and forefinger. thumbs down an indication of rejection or failure. thumbs up an indication of satisfaction or approval. under a person's thumb completely dominated by a person.
Derivatives:
thumbed adj. (also in comb.). thumbless adj.
Etymology: OE thuma f. a WG root swell