ETYM Old Eng. thombe, thoumbe, thume, as. thűma; akin to OFries. thűma, Dutch duim, German daumen, Old High Germ. dűmo, Icel. thumall, Dan. tommelfinger, Swed. tumme, and perhaps to Latin tumere to swell. Related to Thimble, Tumid.
1. The short thick digit of the human hand that is analogous in position to the big toe and differs from the other fingers in having only two phalanges, allowing greater freedom of movement, and being opposable to each of them; also; a corresponding digit in lower animals.
2. The part of a glove or mitten that covers the thumb.
3. A convex molding; ovolo.
4. The thick short innermost digit of the forelimb; SYN. pollex.