- Main Entry:
- 1plumb

- Pronunciation:
-
\ˈpləm\
- Function:
- noun
- Etymology:
- Middle English, from Anglo-French plum, plomb, from Latin plumbum lead
- Date:
- 14th century
: a lead weight attached to a line and used to indicate a vertical direction
—
out of plumb or off plumb : out of vertical or true