What does opposable mean?
Opposable is an adjective meaning capable of being opposed, contrasted, or placed against something else. Its best-known use is anatomical: an opposable digit is one that can move toward or against another digit, as the human thumb can oppose the fingers to form a grip. This arrangement is important for precise grasping and tool use, and opposable digits are also characteristic of many primates. In more general usage, opposable can describe an idea, claim, or proposal that can be challenged or set against another position. It is not, however, a common everyday synonym for “contrary” or “opposite,” and outside specialist contexts it may sound somewhat formal. The word is especially useful when discussing anatomy, animal behavior, or the mechanics of grasping and manipulation.
adjectiveCapable of being opposed, contrasted, or placed against something else. In anatomy, it most commonly describes a digit that can be moved against another digit, as the thumb can be opposed to the fingers.
- Able to be opposed, brought into contrast, or placed against something else.
- In anatomy, able to move one digit against another, as the thumb can be opposed to the fingers.
"The monkey's opposable thumb allows it to grasp branches with considerable precision."
"The species has a strongly opposable thumb, which it uses to manipulate small objects."
"The proposal remains opposable on economic grounds, although its practical effects are limited."
The human thumb is famous as an opposable digit, but opposable toes are also found in many primates, reflecting the evolutionary importance of grasping.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of opposable
Opposable was formed in the 19th century from the Latin-derived word oppose and the suffix -able, meaning “able to be.” It belongs to the same Latin root as oppose, opposite, and opposition, all of which concern placing one thing against another or taking contrasting positions. The anatomical sense developed alongside the word’s broader use for things that can be resisted or challenged.
Related word forms
How opposable is actually used
The word is especially common in anatomical descriptions of the thumb, toes, and other digits. Outside anatomy, it is relatively uncommon and often sounds formal or technical.
Easily confused with opposable
Opposable means capable of being placed against or contrasted with something, whereas opposite usually means situated on the other side or representing a contrasting view.