A weasel is a small, slender mammal with a long body, short legs, and a pointed face. Weasels are fierce hunters despite their size, quick and agile enough to chase mice and rabbits through narrow burrows and tight spaces. Some weasels turn white in winter to blend in with the snow, while keeping the black tip of their tail. They're known for being clever, resourceful predators who can take down prey larger than themselves.

The word also describes someone who avoids responsibility or gets out of commitments through sneaky or dishonest means. When someone weasels out of helping with a group project by making endless excuses, they're acting like a weasel. A person might try to weasel their way out of trouble by twisting the truth or finding technical loopholes. Politicians sometimes use weasel words, which are phrases that sound meaningful but are actually vague or misleading, and are designed to avoid making real promises.

This connection between the animal and the behavior comes from the weasel's reputation for being sneaky and hard to pin down. Just as the animal can slip through the smallest openings, a person who weasels tries to avoid being caught or held accountable.