Plumb
/plʌm/noun
To measure depth with a plumb line, or to make something exactly vertical.
Did you know?Plumb is related to Latin plumbum, meaning “lead,” because early plumb lines were weighted with lead—one of those cases where a tool’s material became the word’s soul.
Etymological Timeline
Proto-Indo-European
PIE
*pleu-
“to flow, float”
Latin
Latin
plumbum
“lead; also the metal used for weights and pipes”
Old French
Old French
plombe
“lead weight; plumb line”
Middle English
English
plomben / plumben
“to test or measure with a plumb line”
Modern English
English
plumb
“to measure depth or align vertically; perfectly vertical”