noun, na-adjective
headstrong; obstinate; bullheaded
Describes a person who is extremely stubborn and refuses to change their mind or admit they are wrong. Often used in a negative sense.
彼は強情頑固で、一度言い出したら絶対に引かない。
He is so headstrong that once he says something, he never backs down.
あの強情頑固な態度には本当に困ったものだ。
That obstinate attitude of his is really troublesome.
Compound of 強情 (ごうじょう, stubborn) and 頑固 (がんこ, stubborn). The exact historical derivation is uncertain, but the combination reinforces the meaning of extreme obstinacy.