central part or heart, especially of a city

to become hollow, cave in, sink in

to become hollow, cave in, sink in: see the kubomu reading above / to decline below a certain point, to become less / to be stuck to be at a loss: see 困る (komaru). / to yield, to submit

plate

center, middle, heart, core (physical center) / center, hub (most important area of activity) / crux, main point

number plate, license plate

(geology) plate tectonics

(baseball, softball) a home plate

tectonic plate

a hotplate (semi-portable stove)