いい加減にしなさい[iikagennishinasai] shape up!
一律減反[ichiritsugentan] reduction in area of rice under cultivation
塩加減[shiokagen] seasoning (with salt)
加減[kagen] addition and subtraction
加減乗除[kagenjoujo] the four arithmetical operations (addition, subtraction, multiplication, division)

加減抵抗器[kagenteikouki] rheostat
火加減[hikagen] condition of fire
経費削減[keihisakugen] cost reduction
軽減[keigen] abatement
激減[gekigen] dropping sharply

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