Etymograph

English

fifteenthly

From fifteenth + -ly.

A compound of fifteenth + -ly

Proto-Germanic *fimftô tehundô

Old English fīftēoþa

Middle English fiftenthe

English fifteenth

Today it means

adv In the fifteenth place; fifteenth in a row.

Language periods are conventional ranges, not dates for this word.

Etymograph / fifteenthly