eighteenth
num.num. the position of number 18 in a list. You use this when talking about dates, floors in a building, or someone's place in a race.
num. the ordinal number corresponding to the cardinal number eighteen. Often functions as a determiner or a noun in date and sequence constructions.
Today is my eighteenth birthday.
She finished in eighteenth place out of fifty runners in the marathon.
The eighteenth century was a period of significant intellectual and social change across Europe, often referred to as the Age of Enlightenment.
Inherited from Middle English eightetenthe, eightetethe, from Old English eahtatēoþa, from Proto-Germanic *ahtudô tehundô. Equivalent to eighteen + -th (ordinal suffix).
Typically functions as an ordinal number; when used in dates, it often follows 'the'.
eightentheighteenthLearners often forget the second 'e' in the middle of the word; it is formed by adding '-th' to 'eighteen'.