Answer:
An idiom is an expression that takes on a figurative meaning when certain words are combined, which is different from the literal definition of the individual words. For example, let's say I said: 'Don't worry, driving out to your house is a piece of cake. ... But in this context, it's a well-known idiom.
Explanation:
'bite off more than you can chew' doesn't mean you bite more than a mouthful of a cake or something else and then struggle to chew
