weasel
n. countablen. a person who is dishonest or sneaky. You use this word for someone who avoids telling the truth or tries to get out of a promise.
n. a person regarded as deceitful, treacherous, or insincere. The figurative sense carries a strong negative connotation and is mainly used in casual speech.
Don't be such a weasel and just tell the truth.
The manager proved to be a total weasel when he blamed his own mistakes on the junior staff.
In political circles, he was known as a weasel who would switch sides the moment he sensed a shift in public opinion, making him impossible to trust in a crisis.
From Middle English wesele, from Old English weosule, from Proto-West Germanic wisulā, from Proto-Germanic wisulǭ. The verb is from c. 1900, from the supposed cunningness of the weasel.
Often used as a pejorative to describe someone who avoids responsibility or uses 'weasel words' to be intentionally vague.