ninth

Pronunciation

• IPA: /naɪnθ/^[1]

Etymology

It is inherited from Middle English nynthe, an alteration, under the influence of nine, of nithe,^[2][3] inherited from Old English nigoþa (“ninth”), nigoða,^[3][2] from nigon, nine; compare seventh.^[3][2] Klein explains the modern form as made on the analogy of fourth by adding -th to nine.^[4]

Earliest recorded meaning

Next after the eighth: before 900 in the OED;^[5] the form nynþe is from about 1300.^[3]

Semantic evolution

As a noun, one of nine equal parts, it is from the late 13th century,^[3][5] and the phrase ninth part from 971.^[5] The ninth day of a month is from 1596.^[5] As a musical interval, an octave and a second, it is from the 1590s (1597).^[3][5]

Timeline

• before 900 – the ordinal.^[5]
• 971 – ninth part.^[5]
• c. 1275 – a ninth part (noun).^[5]
• 1597 – a musical interval.^[5]

Modern meaning

Adjective

1. Coming after the eighth in order; being number nine in a series.

Noun

1. One of nine equal parts of something.
2. (music) An interval of an octave and a second, or a chord containing it.

Word family

• ninthly
• eighty-ninth
• fifty-ninth
• forty-ninth
• ninety-ninth
• seventy-ninth
• sixty-ninth
• thirty-ninth

Related words

• nine
• nineteen
• ninety

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
5. ^ a b c d e f g h i Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press