I. ˈȯr(ˌ)thō, ˈȯ(ə)(ˌ)- adjective
Etymology: orth-
1. : derived from or being an acid in the highest hydrated or hydroxylated form known — compare orth- 3a
2. : relating to, characterized by, or being two neighboring positions in the benzene ring — compare orth- 3b
3. : of, relating to, or being a diatomic molecule (as of hydrogen) in which the nuclei of the atoms are spinning in the same direction — opposed to para
ortho -para conversion
II. adjective
Etymology: by shortening
: orthochromatic