I. -ēn(t)th adjective
Etymology: Middle English nyntenthe, adjective & noun, alteration (influenced by nynetene nineteen) of nyentethe, from Old English nigontēotha, from nigontīene, nigontȳne, nigontēne nineteen + -otha, -tha -th
1. : being number 19 in a countable series
the nineteenth day
— see number table
2. : being one of 19 equal parts into which something is divisible
a nineteenth share of the money
II. noun
( plural nineteenths -ēn(t)s, -ēn(t)ths)
1. : number 19 in a countable series
the nineteenth of the month
2. : the quotient of a unit divided by 19 : one of 19 equal parts of something
one nineteenth of the total
3.
a. : a musical interval of two octaves and a fifth
b. : an organ stop sounding pitches two octaves and a fifth above the keys used