to behave badly or cause trouble
悪いふるまいをする、または問題を引き起こす (warui furumai o suru, mata wa mondai o hikiokosu)
"The kids started to act up during the long car ride."
"長い車の旅の間、子供たちは悪さをし始めました。" (nagai kuruma no tabi no aida, kodomotachi wa **warusa o shihajimemashita**.)
to assume an official leadership role
to do more than what feels easy or safe
to increase the size, amount, or production of something
to turn off a computer or system
to admit that what you said was wrong; to retract something
to gradually stop doing something that no longer fits
