Latinate ordinal number

A Latinate ordinal number is an ordinal number derived from Latin.

In English, these begin primary, secondary, tertiary and quaternary. Further numbers exist, but are rarely used. As ordinal numbers, they are based on the natural numbers, i.e. integers beginning with 1. They cannot be negative, and they cannot be fractions.

Primary means "most important,” secondary means “second most important,” etc. Contrast first which means "the number 1 item in a sequence.”

These are usually adjectives, but they can be changed into adverbs by swapping -ary for -arily. They can be changed into nouns by zero-nominalisation; the primary, the secondary, etc.

The full list is as follows:

1. primary
2. secondary
3. tertiary
4. quaterary
5. quintary
6. sextary
7. septimary
8. octavary
9. nonary
10. undecimary
11. duodecimary

• etc

Related languages typically have numbers that are obvious cognates, e.g. French: primaire, secondaire, tertiaire; German: primär, sekundär, tertiär, etc.