gunto
Describes a dramatic increase, improvement, or change — grades jumping up, temperature dropping sharply, or quality improving noticeably.
💡Exam results — 'My score went gunto up this semester!'
成績がぐんと上がった。
My grades went gunto way up.
The temperature dropped ___ overnight and it felt like winter.
一晩で気温が○○下がって冬のようだ。