plumb C2+ Topic:Mathematics & Measurement US /plʌm/ UK /plʌm/ See IPA manual Homophones plum /plʌm/ Meanings 1 verb to measure depth or to explore thoroughly; exactly vertical Scientists sought to plumb the depths of the trench. Thesaurus Synonyms 1 verb · to measure depth or to... fathomsoundprobegaugeexploremeasurepenetrate Word family Forms plumbedplumblessplumbs Derived forms plumberplumbingplumbery Related forms plummetplumbic Etymology AI details From Old French plomb ('lead, lead weight'), from Latin plumbum ('lead'). A plumb line uses a lead weight to find the vertical or measure depth. plomb Old French plumbum Latin View etymology graph -> Topics Mathematics & Measurement External links Cambridge Dictionary Wiktionary Google Images # plumb **Type:** Word **Level:** C2+ **Part of speech:** verb **IPA (US):** /plʌm/ **IPA (UK):** /plʌm/ ## Meanings 1. to measure depth or to explore thoroughly; exactly vertical ## Examples - Scientists sought to plumb the depths of the trench. ## Synonyms - fathom - sound - probe - gauge - explore - measure - penetrate ## Derived Forms - plumber - plumbing - plumbery ## Related Forms - plummet - plumbic ## Roots and Affixes - Root: plomb - Root: plumbum ## Etymology From Old French plomb ('lead, lead weight'), from Latin plumbum ('lead'). A plumb line uses a lead weight to find the vertical or measure depth. ## AI Etymology Plumb is from Old French plomb ('lead, lead weight'), from Latin plumbum ('lead'). A plumb line uses a lead weight to find the vertical or measure depth. In present-day use, it means to measure depth or to explore thoroughly; exactly vertical. Derived formations include plumber, plumbing, and plumbery. Related vocabulary includes plummet and plumbic. ## Topics - Mathematics & Measurement markdown