I. | ̷ ̷ ̷ ̷| ̷ ̷ adjective
: being one more than 27 in number
twenty-eight years
— see number table
II. pronoun, plural in construction
: 28 countable persons or things not specified but under consideration and being enumerated
twenty-eight are here
twenty-eight were found
III. noun
1. : eight and 20 : four times seven
2.
a. : 28 units or objects
a total of twenty-eight
b. : a group or set of 28
3. : the numerable quantity symbolized by the arabic numerals 28
4. : the 28th in a set or series ; especially : an article of clothing of the 28th size
wears a twenty-eight
IV. noun
: a West Australian yellow-collared parakeet ( Platycercus zonarius semitorquatus )