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

ball (formal dance event)

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

to go in; to come in / 要る: to be necessary, to be required

to enter, go into, get into a place or a thing / to join a group or organization / to be contained (in), to be included (in) / to be a member of a group, set, category

disco ball, mirrorball

ball person

Synonym of 球技 (kyūgi, “ball game”)

(baseball, softball) Synonym of 四球 (shikyū, “walk”)

(idiomatic) A piece of cake; an extremely simple thing, something trivial, a cinch, easy as pie.