I. (ˈ)fif|tēn(t)th adjective
Etymology: Middle English fiftenthe, adjective & noun, alteration (influenced by fiftene ) of fiftethe, from Old English fīftēotha (akin to Old Norse fimmtāndi fifteenth, Gothic fimftataihundin, dative singular neuter), from fīftīene, fīftȳne, fīftēne + -otha, -tha -th
1. : being number 15 in a countable series
the fifteenth day
— see number table
2. : being one of 15 equal parts into which something is divisible
a fifteenth share of the money
II. noun
( plural fifteenths -n(t)s, -n(t)ths)
Etymology: Middle English fiftenthe
1. : number 15 in a countable series
the fifteenth of the month
2. : the quotient of a unit divided by 15 : one of 15 equal parts of something
one fifteenth of the total
3. : a tax of one fifteenth on personal property that formed a part of a grant to the English king from 1272 to 1624
4.
a. : a 2-foot stop in a pipe organ
b. : an interval or compass of a double octave