The short thick finger situated at an angle to the other fingers so it can be opposed to the them, making it possible to pick up and hold things. The thumb is analogous in position to the big toe (the great toe) and similarly has only two phalanges (all the other digits have three).

Old English þuma, from Proto-Germanic *thumon- (source also of Old Frisian thuma, Old Saxon, Old High German thumo, German Daumen, Dutch duim "thumb," Old Norse þumall "thumb of a glove [..]

"to go through" (especially of printed material), 1930, from thumb (n.), though the related sense of "soil or wear by handling" dates from 1640s. Earlier as a verb it meant "t [..]

hitchhike: travel by getting free rides from motorists the thick short innermost digit of the forelimb flick: look through a book or other written material; "He thumbed through the report [..]

the short thick finger on your hand

n. The slider on a window-system scrollbar. So called because moving it allows you to browse through the contents of a text window in a way analogous to thumbing through a book.

grober finger

To dream of seeing a thumb, foretells that you will be the favorite of artful persons and uncertain fortune. If you are suffering from a sore thumb, you will lose in business, and your companions will prove disagreeable. To dream that you have no thumb, implies destitution and loneliness. If it seems unnaturally small, you will enjoy pleasure for a [..]

(n) the thick short innermost digit of the forelimb(n) the part of a glove that provides a covering for the thumb(n) a convex molding having a cross section in the form of a quarter of a circle or of [..]

pollex

When a gladiator was vanquished it rested with the spectators to decide whether he should be slain or not. If they wished him to live, they shut up their thumbs in their fists (polce compresso favor j [..]

Sometimes used of the scroll box, the darker, rounded section of the scroll bar. This can be used to pull a document up or down the screen. In some programs, page numbers or row numbers will appear as [..]

The short thick digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers. (computing) The part of a slider that may be moved line [..]