plumbago Meaning, Definition & Usage

  1. noun used as a lubricant and as a moderator in nuclear reactors
    black lead; graphite.
  2. noun any plumbaginaceous plant of the genus Plumbago

WordNet

Plum*ba"go noun
Etymology
L., from plumbum lead.
Definitions
  1. (Min.) Same as Graphite.
  2. (Bot.) A genus of herbaceous plants with pretty salver-shaped corollas, usually blue or violet; leadwort.

Webster 1913