expression, i-adjective
mentally strong; strong-willed; resilient
Describes a person who has a firm inner core, is not easily swayed, and can endure hardship. Often used positively.
彼女は芯が強いから、どんな困難にも負けない。
She is strong-willed, so she won't be defeated by any hardship.
芯が強い人は、
A mentally strong person doesn't bend their convictions.
Compound of 芯 (core, wick) and 強い (strong). The expression figuratively describes a person whose inner core is firm and unyielding.