Concavity and Half-moon

Concavity noun - A sunken area forming a separate space.

Half-moon and concavity are semantically related In some cases you can use "Half-moon" instead a noun "Concavity".

Nearby Words: concave, concaved

Half-moon noun - The time at which the Moon is at first or last quarter when half its face is illuminated.

Concavity and half-moon are semantically related in arched topic. Sometimes you can use "Concavity" instead a noun phrase "Half-moon".