Welcome to our fun exploration of idioms! An idiom is a phrase that means something different from the words it uses. Today, we’re diving into idioms that include the word “fit” or are related to being fit. These expressions add color to our language and are fun to learn, no matter your age! Fit Idioms Here are 20 fit idioms in English. 1. Fit as a fiddle Meaning: In very good health Example: Grandpa is 90 and fit as a fiddle. 2. Fit for a king Meaning: Very luxurious or grand Example: This dinner is fit for a king. 3.