窪溜まり[kubotamari] hollow
窪み[hekomi] hollow
窪む[kubomu] to cave in
笑窪[ekubo] dimple

窪地[kubochi] pit
盆の窪[bonnokubo] hollow at nape of the neck
落ち窪む[ochikubomu] to sink in
片笑窪[kataekubo] dimple on one cheek

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