stubborn, foolish, firmly
頑 centers on an unyielding quality: stubbornness, foolish obstinacy, or holding firmly to a position or state.
頑 combines 元 (origin, head) with 頁 (head, page), suggesting a hard-headed or stubborn quality. The exact historical development is uncertain, but the component combination fits the meaning of obstinacy.
The left side 元 suggests a person's head, and the right side 頁 is also a head. Picture two hard heads butting against each other, refusing to give way: that's stubbornness.
For ガン, imagine a stubborn gun that refuses to fire unless you hold it firmly: gun -> ガン, and the gun's obstinacy matches the kanji's meaning.
to persevere; to persist; to keep at it; to hang on; to hold out; to do one's best
solid; firm; stout; burly; strong; sturdy
stubborn; obstinate; pigheaded
obstinate; stubborn; mulish; die-hard; bigoted
stubborn; dogged; persistent; tenacious
robust; fit and healthy; strong; sturdy
stubbornly; firmly; determinedly; obstinately; resolutely; adamantly
bigoted; obstinate; stubborn; pigheaded
an extra effort; going the extra mile; one final push
obstinate; stubborn; hard-headed; pigheaded; incapable of making sound judgements because of a narrow, inflexible and obstinate mentality
headstrong; obstinate; bullheaded
being of very robust health
stubborn and ignorant
stubborn; obstinate; adamant; immovable
stubborn person; obstinate person; pig-headed person
stubborn (obstinate) father; pig-headed old man
do your best; go for it; hang in there; keep at it
tenacity; endurance
attitude that one must keep going no matter what
hard worker; person who perseveres; person who doesn't give up; eager beaver; bitter-ender