What's the term for a word used in casual conversation that differs from its actual meaning, e.g. using "rim" to mean "wheel" [closed]

Solution 1:

This could also be an example of metonymy:

a figure of speech that consists of the use of the name of one object or concept for that of another to which it is related, or of which it is a part, as “scepter” for “sovereignty,” or “the bottle” for “strong drink,” or “count heads (or noses)” for “count people.”