What does beaver mean?
The beaver is a large, semi-aquatic rodent native to North America and Eurasia, renowned for its remarkable engineering behaviour. With a stout body, dense waterproof brown fur, webbed hind feet, and a distinctive broad, flat, scaly tail, it fells trees and builds dams and lodges that reshape entire waterways, creating wetlands that benefit countless other species. Two species exist: the North American beaver (Castor canadensis) and the Eurasian beaver (Castor fiber). Beyond the animal itself, 'beaver' historically referred to its highly prized pelt, which fuelled the North American fur trade and even served as currency among trappers. By extension, the word describes a tireless worker — the idiom 'eager beaver' captures someone enthusiastically industrious. Whether encountered in nature documentaries, history books about the fur trade, or everyday conversation about busy colleagues, 'beaver' is a vivid word tied to one of nature's most impressive builders.
A large semi-aquatic rodent of the genus Castor, having a broad flat tail, webbed hind feet, and thick brown fur, noted for gnawing trees and building dams and lodges.
"The beaver slapped its tail on the water before diving beneath the surface."
Also used for the animal's pelt or fur, especially in historical contexts relating to the fur trade.
(Informal) A person who is exceptionally diligent or enthusiastic about work, especially in the phrase 'eager beaver'.
"Every office has its eager beavers who volunteer for everything."
Regular plural; used both for multiple animals and, informally, for multiple hardworking people.
"Several beavers have colonised the river since the reintroduction programme began."
Beavers were once so prized for their fur that they drove much of the early exploration of North America — and their dams are now celebrated as natural flood defences.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of beaver
The English word 'beaver' descends from Old English 'beofor' or 'befer', which traces back through Proto-Germanic '*bebruz' to the Proto-Indo-European root '*bhebhrus', a reduplicated form related to the brown colour of the animal's coat. It is a true Germanic native word, with cognates across the Germanic languages including German 'Biber', Dutch 'bever', and Swedish ' bäver', and it shares distant Indo-European kinship with Latin 'fiber' and Greek 'kastor' (the source of 'castor'). The word has been in continuous use since the earliest recorded stages of English, reflecting the animal's long importance to northern European peoples.
How beaver is actually used
The informal sense describing a hardworking person is casual and friendly rather than formal; 'eager beaver' is a well-established idiom. In British English the same senses apply. Note that in some coarse slang registers the word carries an anatomical sense, so context matters in informal speech.
Easily confused with beaver
An otter is a sleek, carnivorous aquatic mammal that hunts fish, whereas a beaver is a herbivorous rodent with a broad flat tail that builds dams.