Plummet :: Plummet (n.) A piece of lead formerly used by school children to rule paper for writing.
Plumming :: Plumming (n.) The operation of finding, by means of a mine dial, the place where to sink an air shaft, or to bring an adit to the work, or to find which way the lode inclines..
Plummy :: Plummy (a.) Of the nature of a plum; desirable; profitable; advantageous.