i refute the above:

muffin, is nothing like muff, but both 'muffin' and 'muff' are either the correct or colloquial terminology for what they are commonly associated with.

a seat may well be something you sit on, but when it refers to the part of the bicycle with which it is associated, it is a saddle.
a horsen saddle is something you 'sit' on (read:seated; base:seat) but by using the correct terminology, i know that you were on top of a horse.