What does plumbness mean?
Plumbness means the state or quality of being plumb, particularly of being exactly vertical. A wall, pillar, or other structure is said to have plumbness when it stands perpendicular to the horizontal or follows a true vertical line. The term is used especially in surveying, construction, and engineering, where small deviations from a vertical alignment can affect safety or structural accuracy. It can also refer more generally to the degree of proper alignment of an object. Plumbness is uncommon in everyday speech; people usually say verticality, or describe something as vertical, upright, or true. The word is related to plumb, which describes something aligned vertically and also gives us the familiar term plumb line, a weight suspended from a string to establish a true vertical reference.
nounThe state or quality of being plumb, especially of being exactly vertical. The word is rare and chiefly occurs in technical or formal writing.
- The quality or state of being exactly vertical.
- The degree to which something is plumb or properly aligned.
"The surveyor's measurements confirmed the plumbness of the tower's western wall."
"Even a slight deviation can affect the plumbness of the entire framework."
"The engineers tested the wall's plumbness before the decorative stonework was installed."
The plural is rarely needed or encountered in ordinary usage.
"The surveyors recorded the plumbnesses of the tower's four corners."
Plumbness is the word for a line's perfect verticality—the precision once checked with a weight on a string.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does plumbness come from?
Plumbness was formed in English by adding the suffix -ness to plumb. The word plumb came through Anglo-French from Latin plumbum, meaning "lead," a material historically used in plumb lines because of its weight. The same Latin source also produced English plummet, another instrument associated with establishing depth or vertical measurement.
Related word forms
How plumbness is actually used
This is a rare noun, normally used in surveying, construction, engineering, or other technical contexts. In general writing, verticality is more natural.