orthohydrogen: Meaning and Definition of

or•tho•hy•dro•gen

Pronunciation: (ôr"thu-hī'dru-jun), [key]
— n. Physics, Chem.
  1. the form of molecular hydrogen in which the nuclei of the two hydrogen atoms contained in the molecule have spins in the same direction. Cf.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.