plumb_line
1. [ noun ] a cord from which a metal weight is suspended pointing directly to the earth's center of gravity; used to determine the vertical from a given point
Synonyms: perpendicular
Related terms: cord plumb_rule lead_line plumb_bob
Similar spelling:   plump_in
  plumb_level
  plumbable
  plumb_rule
  plumbic
  plumbism
  plumbing
  plumber
  plumbed
  plumbery
  plumb_bob
  Plumbaginales