I. | ̷ ̷ ̷ ̷| ̷ ̷ adjective
: being one more than 63 in number
sixty-four years
— see number table
II. pronoun, plural in construction
: 64 countable persons or things not specified but under consideration and being enumerated
sixty-four are here
sixty-four were found
III. noun
1. : four and 60 : four times 16 : the square of 8 : the cube of 4
2.
a. : 64 units or objects
a total of sixty-four
b. : a group or set of 64
3. : the numerable quantity symbolized by the arabic numerals 64
4. : the 64th in a set or series