悪習[akushuu] bad habit
悪習慣[akushuukan] bad habit
演習[enshuu] practice
演習問題[enshuumondai] practice problem
演奏練習[ensourenshuu] musical rehearsal

学習[gakushuu] study
学習者[gakushuusha] learner
学習塾[gakushuujuku] private night-school
学習用[gakushuuyou] tutorial
学習用ヘルプ[gakushuuyouherupu] tutorial help

逸速く[ichihayaku] promptly
音速[onsoku] speed of sound
加速[kasoku] acceleration
加速運動[kasokuundou] accelerated motion
加速度[kasokudo] acceleration

快速[kaisoku] high speed
快速電車[kaisokudensha] high-speed train
角速度[kakusokudo] angular velocity
急速[kyuusoku] rapid (e.g. progress)
減速[gensoku] deceleration