a gauge for measuring the depth of grooves or holes or other concavities
the extent downward or backward or inward
degree of psychological or intellectual profundity
(usually plural) the deepest and most remote part
a measuring instrument for measuring and indicating a quantity such as the thickness of wire or the amount of rain etc.
measure precisely and against a standard
the intellectual ability to penetrate deeply into ideas
the distance between the rails of a railway or between the wheels of a train
