PLUMB, noun plum. [Latin plumbum, lead; probably a clump or lump.]
A mass of lead attached to a line, and used to ascertain a perpendicular position of buildings and the like. But the word as a noun is seldom used, except in composition. [See Plumb-line.]
PLUMB, adjective Perpendicular, that is, standing according to a plumb-line. The post of the house or the wall is plumb [This is the common language of our mechanics.]
PLUMB, adverb In a perpendicular direction; in a line perpendicular to the plane of the horizon. The wall stands plumb
PLUMB down he falls.
1. Directly; suddenly; at once; as a falling mass; usually pronounced plump. He fell plumb into the water.
PLUMB, verb transitive To adjust by a plumb-line; to set in a perpendicular direction; as, to plumb a building or a wall.
1. To sound with a plummet, as the depth of water. [Little used.]