Prolonged means continuing for a long time — often longer than you wanted. A prolonged illness, a prolonged silence, prolonged applause. It is the adjective from the verb prolong, to make something last longer. Doctors use it a great deal: prolonged fever, prolonged exposure. Though actually, long and prolonged are not quite twins. A long meeting is just a fact about the clock; a prolonged meeting often hints that it was stretched, maybe painfully, past the natural end. You can praise prolonged applause; you rarely praise a prolonged wait.

長時間的、持續很久的