The "nom" is your clue that the word has do to with names or labels. Nominally (in name only), denomination (the label giving the value), nominate (to be named

The "nom" is your clue that the word has do to with names or labels. Nominally (in name only), denomination (the label giving the value), nominate (to be named to a position), etc. I think even "number" (a label for a quantity) and "name" come from the same root. It follows that a misnomer is a "bad name," usually stemming from a misunderstanding about an origin. E.g., a firefly isn't a fly, a peanut isn't a nut, a starfish isn't a fish, a shooting star isn't a star, etc.