凹 - concave, hollow, sunken

unevenness; roughness; ruggedness; bumpiness

hollow; cavity; dent; depression

unevenness; bumpiness; roughness; ruggedness

to be dented; to be indented; to yield; to give; to sink; to collapse; to cave in

concave lens

concavity

odd couple; incongruous couple

when the right conditions are fulfilled, things will turn out well on their own; a sunken place will collect water

developmental irregularities; developmental disorder; neurodiversity

Africa Scream (film)

intaglio plate

to lose heart; to be discouraged; to be dejected; to be exhausted; to be tired out