plumb

/ˈpləm/

Middle English, from Anglo-French plum, plomb, from Latin plumbum lead

noun

  1. a lead weight attached to a line and used to indicate a vertical direction

adverb

  1. straight down or up : vertically

  2. to a complete degree : absolutely

  3. in a direct manner : exactly; also : without interval of time : immediately

verb

  1. to weight with lead

  2. to measure the depth of with a plumb

  3. to examine minutely and critically