使内凹
使成拱形（cove的动词过去分词）

Cove \Cove\, v. t. [imp. & p. p. {Coved} (k?vd); p. pr. & vb. n.
{Coving}.] (Arch.)
To arch over; to build in a hollow concave form; to make in
the form of a cove.

The mosques and other buildings of the Arabians are
rounded into domes and coved roofs. --H.
Swinburne.

{Coved ceiling}, a ceiling, the part of which next the wail
is constructed in a cove.

{Coved vault}, a vault composed of four coves meeting in a
central point, and therefore the reverse of a groined
vault.