No, it is not a noun. Flimsy is an adjective meaning insubstantial or cheap.
It is an adjective. Nouns are persons, places or things and verbs are actions. Flimsy (and other adjectives) modify nouns.
you have to be a flimsy before a leader
Flimsy+miserable = Flimsable
flimsy is it greek or latin
His flimsy excuses just don't hold water. The flimsy walls shook when the train rolled past.
the flimsy paper ripped with ease.
"Flimsy" is an adjective. It describes something that is weak or easily broken.
The flimsy wooden stick broke the second David stepped on it.
Paier's jacket was too flimsy. It wasnt enough to keep him warm.
flimsiness
Saying that your book report blew out the car window is a flimsy excuse.
A flimsy person is a person which is weak. Whether that person is weak, as in strength wise, or in weak of personality, the person isn't strong. Not emotionaly. A person who is afraid, and longs ever so much to be brave.