Like a Marmoset but completely different. These are things women have (boobs or a vagina), or it could be a penis. Anything sexual really, even a bummhole.
This word was originally made/ thought of back when I was in pre-school and it became part of a secret language with my friend. In later years the meaning of the words in that language were changed to suit our conversations and so it was born!
My God she has massive Mwahmosetts!
Did you see the size of Harry's Mwahmosett? - I know it fitted right into my Mwahmosett!