sole of the foot

head over heels

to be head over heels

(management) key performance indicators; KPI

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)

an area with sides higher than the center: an indentation, a depression, a dip, a divot, a hole / (slang) female genitalia, the vagina

a sunken center / a place or object with a sunken center