Unsuitable or inappropriate (for a situation, social standing, ability, etc.); not matching what is fitting or deserved.
若すぎる彼にその役職は不相応だ。
That position is inappropriate for someone as young as him.
彼女にはあの高級マンションは不相応だと感じた。
I felt that luxury apartment was not suitable for her.
収入に見合わない買い物をするのは不相応だ。
Buying things beyond one's income is inappropriate.