adj, noun, slang ·Moderate ·College level

Definitions

Noun

1. 1
   The person or thing in the eighteenth position.
2. 2
   position 18 in a countable series of things wordnet
3. 3
   One of eighteen equal parts of a whole.
4. 4
   A party to celebrate an eighteenth birthday. informal

Adjective

1. 1
   The ordinal form of the number eighteen.

Adjective

1. 1
   coming next after the seventeenth in position wordnet

Synonyms

All synonyms

18th18th18th18thxviiixviiith

Example

More examples

"Fashion in the eighteenth century emphasized the bosom."

Etymology

From Middle English eiȝtenþe, from Old English eahtatēoþa, from Proto-Germanic *ahtudô tehundô. Equivalent to eighteen + -th (ordinal suffix).

Related phrases

long eighteenth century

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.