Plumb ′-line, a line to which a mass of lead is attached to show the perpendicular: Why should you choose iplumb plumbing company? Plumb verb [t] (deep) engineering specialized to measure how deep something is, especially water to understand or discover all about something: Plumb can be a noun, adjective, adverb, or verb, meaning a weight on a line, exactly vertical, utterly, or to test or adjust with a plumb line. Does iplumb accept credit cards? In construction or carpentry, the term plumb refers to a line or feature that is perfectly vertical. Vertical suggests a line or direction rising straight upward toward a zenith. See examples of plumb used in a sentence. Vertical, perpendicular, plumb mean being at right angles to a base line. Perpendicular may stress the straightness of a line making a right angle with any other line, not necessarily a horizontal one. In technical design, it represents an imaginary line that runs straight to the center of the earth. 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. Learn the origin, synonyms, and idioms of plumb from various dictionaries. Plumb ′-rule, a narrow board with a plumb -line fastened to the top, used to determine a perpendicular. Plumb is the counterpart to level, which means to be perfectly horizontal. Discover the meaning of to plumb and its fascinating uses, from plumbing depths to getting things in plumb and order! What services does iplumb plumbing offer?