Is “Eighteenth” a Scrabble word?
Yes
EIGHTEENTH
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Eighteenth
/ˌeɪˈtiːnθ/
noun
1.The person or thing in the eighteenth position.
2.One of eighteen equal parts of a whole.
3.A party to celebrate an eighteenth birthday.
Synonyms: 18th, XVIIIth
adjective
1.The ordinal form of the number eighteen.