An intransitive verb meaning to increase in intensity, to worsen, or to become aggravated (used for illness, conflicts, emotions, etc.).
風邪が高じて入院することになった。
The cold worsened and he had to be hospitalized.
冗談が度を越して喧嘩が高じてしまった。
A joke went too far and the argument escalated.
彼の不満が高じて退職を決めたらしい。
His dissatisfaction grew to the point that he apparently decided to quit.