"Concaveness" is a word in ENGLISH

A hollow vessel, of various forms and materials, used in the arts or manufactures, as that used by glass grinders …

A hollow; an arched vault; a cavity; a recess.

Hollow; void of contents.

Hollow and curved or rounded; vaulted; -- said of the interior of a curved surface or line, as of the …

To make hollow or concave.

Concave or hollow on both sides; double concave.

To arch over; to build in a hollow concave form; to make in the form of a cove.

A low spot surrounded by elevations; a depressed part of a surface; a concavity; a channel.

Depressed; concave; gaunt; sunken.

adj. concave, hollow.

n. the tubular, earthenware lining of a well, well casing. adj. /NA-/ concave, hollow.

siklob - Hole, cavity, depression; to be or become concave, hollow, (cf. lángub, búhò, lúpyak).

A hollow or concave utensil for holding anything; a hollow receptacle of any kind, as a hogshead, a barrel, a …