beaver
noun
a large, amphibious rodent of the genus Castor, having sharp incisors, webbed hind feet, and a flattened tail, noted for its ability to dam streams with trees, branches, etc.
Used to describe actions that started in the past and continue into or have direct relevance to the present.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"They have beavered away trying this and trying that and the formulations have changed over the last 50 years, but not radically."
From BBC ● Apr. 11, 2011