ortho-

English

Etymology

Ancient Greek ὀρθός (orthos).

Prefix

ortho-

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

[+] English words prefixed with ortho-

• orthocoking
• orthodontis
• orthokinesis
• Ortheptera
• orthosteric

---

French

Etymology

Ancient Greek ὀρθός (orthos).

Prefix

ortho-

1. right

Derived terms

• orthodentie
• orthodentiste
• orthopédie

Pronunciation