'Penta-' definitions:

Definition of 'Penta-'

From: GCIDE
  • Penta- \Pen"ta-\, pref. [Gr. penta-, a later combining form of pe`nte five. See Five.]
  • 1. A combining form denoting five; as, pentacapsular; pentagon. [1913 Webster]
  • 2. (Chem.) Denoting the degree of five, either as regards quality, property, or composition; as, pentasulphide, containing five sulfur atoms; pentoxide, containing five oxygen atoms, etc. Also used adjectively. [1913 Webster]