Plumb
Plumb [ pluhm ] [ noun, verb ] MEANING : 1. (n.) lead hung on a string to establish the vertical line or to determine the depth of water 2. (adj.) exactly vertical or perpendicular 3. (intr. v.) to work as a plumber 4. (tr. v.) to make vertical 5. (tr. v.) to examine closely USAGE EXAMPLE 1 : He was an experienced fisherman and would plumb the depth of the lake where he intended to fish.