beach ball

play, amuse oneself, enjoy oneself / spend one's time idle, do nothing / for an item not to be in use, be spare or idle

cardboard (corrugated)

beach

a flip-flop

a sea, an ocean / a lake / (figuratively) an object covering over a large area, as in 血の海 (chi no umi, “pool of blood”) or 火の海 (hi no umi, “sea of fire”)

ball (sphere) / (basebal) ball (pitch that falls outside the strike zone)

bowl

Short for ボール紙 (bōru-gami): non-corrugated cardboard, pasteboard / Short for 段ボール (danbōru): corrugated cardboard

ball (formal dance event)