Ortho-

Origin

Ancient Greek ὀρθός.

Full definition of ortho-

Prefix

1. straight, right, proper
2. (chemistry) Having an extra proportion of water
3. (chemistry) in isomeric benzene derivatives, having the two substituents in adjacent positions (compare meta- and para-)
4. (physics) of any molecule of the form X₂ in which the two nuclei have parallel spin

Derived terms

• orthopedics
• orthodox
• orthographic
• orthotic
• orthosteric