The meaning of PLUMB is a lead weight attached to a line and used to indicate a vertical direction. How to use plumb in a sentence.

plumb verb [T] (DEEP) engineering specialized to measure how deep something is, especially water to understand or discover all about something:

PLUMB definition: a small mass of lead or other heavy material, as that suspended by a line and used to measure the depth of water or to ascertain a vertical line. See examples of plumb …

1. (Building) a weight, usually of lead, suspended at the end of a line and used to determine water depth or verticality 2. (Building) the perpendicular position of a freely suspended plumb line …

Plumb is used to give emphasis to an adjective or verb that describes a feeling or condition.

Dec 11, 2025 · Adverb plumb (not comparable) In a vertical direction; perpendicularly. (informal) Squarely, directly; deeply, completely.

plumb /plʌm/ n. [countable] Building, Surveying a small mass of lead hung on a line and used to measure the depth of water or to make sure a line is straight up and down.