NINETIETH
ninetieth, th
(adjective) the ordinal number of ninety in counting order
ninetieth
(noun) position 90 in a countable series of things
Source: WordNet® 3.1
Adjective
ninetieth (not comparable)
The ordinal form of the number ninety.
Abbreviations
• 90th, 90th
Noun
ninetieth (plural ninetieths)
The person or thing in the ninetieth position.
One of ninety equal parts of a whole.
Source: Wiktionary
Nine"ti*eth, a.
1. Next in order after the eighty-ninth.
2. Constituting or being one of ninety equal parts.
Nine"ti*eth, n.
1. The quotient of a unit divided by ninety; one of ninety equal
parts of anything.
2. The next in order after the eighty-ninth.
Source: Webster’s Unabridged Dictionary 1913 Edition