to be truant; to slack off; to play hooky; to skip school; to cut class; to skip out
授業をさぼって映画を見に行った。
I skipped class and went to see a movie.
最近筋トレをさぼり気味だ。
I've been slacking off on weight training lately.
さぼらずに毎日練習しよう。
Let's practice every day without slacking off.