是等[korera] these
其等[sorera] those (near the second person)
等閑[naozari] neglect
悪平等[akubyoudou] misguided equality
位階勲等[ikaikuntou] court rank and honors

一等[ittou] first-class
１等軍曹[ittougunsou] sergeant first-class
１等国[ittoukoku] first-class power
１等車[ittousha] first-class carriage (coach)
１等賞[ittoushou] first place prize

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