Ordinal Number
"In linguistics, ordinal numbers are words representing position or rank in a sequential order. The order may be of size, importance, chronology, and so on. In English, they are adjectives such as 'third' and 'tertiary'. They differ from cardinal numbers, which represent quantity."
Spatial/chronological | first | second | third | fourth | fifth | sixth | seventh | eighth | ninth | tenth | eleventh | twelfth |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Precedence/effect | primary | secondary | tertiary | quaternary | quinary | senary | septenary | octonary | novenary | decenary | undenary | duodenary |
Greek prefix | proto- | deutero- | trito- | tetarto- | pempto- | ecto- | ebdomo- | ogdoo- | enato- | decato- | endecato- | dodecato- |
Source: http://en.wikipedia.org/wiki/Ordinal_number_%28linguistics%29