一粒[hitotsubu] (a) grain
一粒子既約[ichiryuushikiyaku] one particle irreducible (physics)
一粒種[hitotsubudane] an only child
雨粒[amatsubu] raindrop
穀粒[kokuryuu] kernel

素粒子[soryuushi] elementary particle
素粒子加速器[soryuushikasokuki] particle accelerator
大粒[ootsubu] large grain
長粒米[chouryuumai] long grain rice
麦粒腫[bakuryuushu] sty (on the eyelid)

ムール貝[muurugai] moule
一枚貝[ichimaigai] univalve
烏貝[karasugai] cockscomb pearl mussel (Cristaria plicata)
貝ボタン[kaibotan] mother-of-pearl button
貝貨[baika] shell money

貝がら[kaigara] shell
貝柱[kaibashira] adductor muscle
貝毒[kaidoku] shellfish poison
貝類[kairui] shellfish