'Sexagenarian' definitions:

Definition of 'sexagenarian'

From: WordNet
adjective
Being from 60 to 69 years old; "the sexagenarian population is growing"
noun
Someone whose age is in the sixties

Definition of 'Sexagenarian'

From: GCIDE
  • Sexagenarian \Sex`a*ge*na"ri*an\, n. [See Sexagenary.] A person who is sixty years old. [1913 Webster]

Synonyms of 'sexagenarian'

From: Moby Thesaurus