sixty-fourth

From sixty-four +‎ -th (ordinal suffix).

• (UK) IPA^(key): /ˌsɪksti ˈfɔːθ/
• (US) IPA^(key): /ˌsɪksti ˈfɔɹθ/

sixty-fourth

1. The ordinal form of the number sixty-four, describing a person or thing in position number 64 of a sequence.

   The answer appears on the sixty-fourth page of the book.

   She finished sixty-fourth in the race.

English ordinal numbers may function as either an adjective or as a noun, and almost never appear in the plural.

• 64th, 64^th

sixty-fourth (plural sixty-fourths)

1. One of sixty-four equal parts of a whole.

   A sixty-fourth of 1280 is 20.