From Longman Dictionary of Contemporary Englishbeaverbea‧ver1 /ˈbiːvə $ -ər/ noun [countable] 
HBAa North American animal that has thick fur and a wide flat tail, and cuts down trees with its teeth → eager beaver at eager(2)
HBAa North American animal that has thick fur and a wide flat tail, and cuts down trees with its teeth → eager beaver at eager(2)Examples from the Corpus
beaver• Whatever its benefits, a beaver lake is a conspicuous and characteristic feature of the landscape.• These meant that a beaver had been here recently.• This will tend to apply to all the logs placed by any beaver bearing this particular mutation.• A prime beaver pelt was worth $ 6 to $ 8 a pound.• Although retired, Selwyn Hopkins was a regular beaver where gardening was concerned.• Like the beaver skins, it had never had a function in this domesticated place.• The beaver skins that Oliver had sent her from Deadwood were a trouble.• Luiza and Freddi were there, Luiza muffled up in a huge and unflattering beaver lamb coat that had seen better days.beaverbeaver2 verb → beaver away→ See Verb tableExamples from the Corpus
beaver• To do the work requires an enormous amount of effort beavering away among old records, checking, copying and encoding.• Information can be automatically kept up to date, and will allow individuals to co-operate on projects instead of beavering away in isolation.• The Doc's patented micro-organisms were beavering away inside, keeping her at the peak of perfection.• You will enjoy beavering away to find out.Origin beaver Old English beofor 