遺失[ishitsu] loss
遺失物[ishitsubutsu] lost article
一失[isshitsu] disadvantage (defect, error)
一得一失[ittokuisshitsu] gaining some and losing some
栄養失調[eiyoushicchou] malnutrition

過失[kashitsu] error
見失う[miushinau] to lose sight of
失う[ushinau] to lose
失する[shissuru] to lose
失せる[useru] to disappear

クスクス笑う[kusukusuwarau] to giggle
けらけら笑う[kerakerawarau] to cackle
げらげら笑う[geragerawarau] to guffaw
一笑[isshou] laugh
一笑に付す[isshounifusu] to laugh (someone) down

一顰一笑[ippinisshou] (a) mood
可笑しい[okashii] funny
含み笑い[fukumiwarai] suppressed laugh
嬉笑[kishou] happy laughter
戯笑[gishou] playful laughter