Plural of Terminus
“Terminus” has two accepted plural forms: “terminuses” and the Latin-derived “termini.” Because both are established, this is a genuine competing-plural case rather than a simple add-s rule.
Both “terminuses” and “termini” are accepted plurals of “terminus.” Choose the form that fits your audience or house style, and keep it consistent within the same context.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| one endpoint or terminal point | terminus | Use the singular form. |
| regular English plural | terminuses | Accepted plural. |
| Latin-derived plural | termini | Also accepted. |
Quick tests
Meaning / construction test
Do you need the plural of “terminus”?
If yes: Use either “terminuses” or “termini,” then keep the choice consistent with audience or house style.
If no: Use singular “terminus” for one.
Caveat: Both plural forms are accepted; the choice can depend on register, field, or house style rather than a universal correctness rule.
Examples
The line has one terminus here.
One endpoint takes “terminus.”
The map marks two terminuses.
“Terminuses” is an accepted regular English plural.
The technical note labels the termini.
“Termini” is also an accepted plural.
Further guidance
Core difference
Use either “terminuses” or “termini” as the plural of “terminus”; both are documented.
Fast Test
If a publication or field consistently prefers classical plurals, “termini” may fit; otherwise “terminuses” is also standard.
Usage Boundary
Do not claim that one of the two accepted plurals is universally the only correct form.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Terminus — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Learner-dictionary evidence for the accepted plurals “terminuses” and “termini.”