thumb

[thuhm] /θʌm/

noun

the short, thick, inner digit of the human hand, next to the forefinger.

the corresponding digit in other animals; pollex.

the part of a glove or mitten for containing this digit.

Architecture. an ovolo or echinus molding.

verb (used with object)

to soil or wear with the thumbs in handling, as the pages of a book.

to glance through (the pages of a book, leaflet, etc.) quickly.

to play (a guitar or other instrument) with or as with the thumbs.

(of a hitchhiker) to solicit or get (a ride) by pointing the thumb in the desired direction of travel.

Idioms

all thumbs, awkward; clumsy; bungling:

The visitor almost knocked over a vase and seemed to be all thumbs.

10.

thumb one's nose,

to put one's thumb to one's nose and extend the fingers as a crudely defiant or contemptuous gesture.
to express defiance or contempt; dismiss or reject contemptuously.

11.

thumbs down, a gesture or expression of dissent or disapproval:

We turned thumbs down to that suggestion.

12.

thumbs up, a gesture or expression of assent or approval.

13.

under one's thumb, under the power or influence of; subordinate to.

Also, under the thumb of.

Origin

before 900; Middle English; Old English thūma; cognate with Dutch duim, Old Saxon, Old High German dūmo (German Daumen), Old Norse thumall; akin to Latin tumēre to swell (tumor)

Related forms

thumbless, adjective

thumblike, adjective

Examples from the web for thumb

Press your thumb into center of each cookie ball, making a small well.
Don't use your thumb to direct water from a bare hose end.
She then pierced a hole in the center of the pancake with the back of her thumb, and laid it in the skillet.
These little butterflies are plentiful and tiny-some are no larger than my thumb-and share similar markings across species.
They eat bamboo, grasping shoots with a pseudo thumb.
He also developed the technique of using a palette knife-and even his thumb-to apply and shape paint.
In earlier drafts of the script, there was a plot line that involved a new form of credit card: your thumb.
There is a simple rule of thumb that can be applied toward multiple solutions: don't expend energy in order to dissipate energy.
The first time, they were small tubers, no bigger than my thumb in diameter.
The best example of this form is the carpometacarpal joint of the thumb.

British Dictionary definitions for thumb

thumb

/θʌm/

noun

the first and usually shortest and thickest of the digits of the hand, composed of two short bones Technical name pollex, related adjective pollical

the corresponding digit in other vertebrates

the part of a glove shaped to fit the thumb

(architect) another name for ovolo

all thumbs, clumsy

thumbs down, an indication of refusal, disapproval, or negation: he gave the thumbs down on our proposal

thumbs up, an indication of encouragement, approval, or acceptance

under someone's thumb, at someone's mercy or command

verb

(transitive) to touch, mark, or move with the thumb

10.

to attempt to obtain (a lift or ride) by signalling with the thumb

11.

when intr, often foll by through. to flip the pages of (a book, magazine, etc) perfunctorily in order to glance at the contents

12.

thumb one's nose at, to deride or mock, esp by placing the thumb on the nose with fingers extended

Derived Forms

thumbless, adjective
thumblike, adjective

Word Origin

Old English thūma; related to Old Saxon thūma, Old High German thūmo, Old Norse thumall thumb of a glove, Latin tumēre to swell

Word Origin and History for thumb

Old English þuma, from West Germanic *thumon- (cf. Old Frisian thuma, Old Saxon, Old High German thumo, German Daumen, Dutch duim "thumb," Old Norse þumall "thumb of a glove"), literally "the stout or thick (finger)," from PIE *tum- "swell" (cf. Latin tumere "to swell," tumidus "swollen;" Avestan tuma "fat;" see thigh). For spelling with -b (attested from late 13c.), see limb.

To be under (someone's) thumb "be totally controlled by that person" is recorded from 1580s. Thumbs up (1887) and thumbs down (1906) were said to be from expressions of approval or the opposite in ancient amphitheaters, especially gladiator shows, where the gesture decided whether a defeated combatant was spared or slain. But the Roman gesture was merely one of hiding the thumb in the hand or extending it. Perhaps the modern gesture is from the usual coachmen's way of greeting while the hands are occupied with the reins.

"to go through" (especially of printed material), 1930, from thumb (n.), though the related sense of "soil or wear by handling" dates from 1640s. Meaning "to hitchhike" is 1939; originally the thumb pointed in the direction one wished to travel. Related: Thumbed; thumbing. To thumb (one's) nose as an expression of derision is recorded from 1903.

thumb in Medicine

thumb (thŭm)
n.
The short thick digit of the human hand, next to the index finger and opposable to each of the other four digits.

Slang definitions & phrases for thumb

thumb

noun

A marijuana cigarette; joint (1960s+ Narcotics)

verb

(also thumb a ride) To solicit rides along a highway by pointing with one's thumb in the direction one wishes to travel; hitchhike (1939+)

Related Terms

a green thumb, stick out

[narcotics sense fr the fact that one sucks the cigarette as a baby does its thumb]

thumb in Technology

processor
An extension to the Advanced RISC Machine architecture, announced on 06 March 1995 by Advanced RISC Machines Ltd. By identifying the critical subset of the ARM instruction set and encoding it into 16 bits, ARM has succeeded in reducing typical program size by 30-40% from ARM's already excellent code density. Since this Thumb instruction set uses less memory for program storage, cost is further reduced.
All Thumb-aware processor cores combine the capability to execute both the 32-bit ARM and the 16-bit Thumb instruction sets. Careful design of the Thumb instructions allow them to be decompressed into full ARM instructions transparently during normal instruction decoding without any performance penalty. This differs from other 32-bit processors, like the Intel 486SX, with a 16-bit data bus, which require two 16-bit memory accesses to execute every 32-bit instruction and so halve performance.
The patented Thumb decompressor has been carefully designed with only a small amount of circuitry additional to the existing instruction decoder, so chip size and thus cost do not significantly increase. Designers can easily interleave fast ARM instructions (for performance critical parts of a program) with compact Thumb code to save memory.
(1995-03-14)

jargon
The slider or "bubble" 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.
[Jargon File]
(1995-03-14)

Idioms and Phrases with thumb

thumb

also see:

Encyclopedia Article for thumb

pollex

short, thick first digit of the human hand and of the lower-primate hand and foot. It differs from other digits in having only two phalanges (tubular bones of the fingers and toes). The thumb also differs in having much freedom of movement and being opposable to tips of other digits. The corresponding first digit (most medial digit) in other vertebrates is also called the thumb, especially if it has some manipulative or special ability (e.g., in the raccoon and the bat)

Learn more about pollex with a free trial on Britannica.com