na-adjective, noun
boasting of one's strength; proud of one's strength
Describes a person who is proud of their physical strength and often shows it off. Can be used as a noun or adjectival noun.
彼は力自慢で、よく重いものを持ち上げて見せる。
He is proud of his strength and often shows off by lifting heavy things.
あの力自慢の
That man who boasts of his strength always challenges people to arm wrestling.