(sixties)
Frequency: The word is one of the 700 most common words in English.
1.
Sixty is the number 60.
...the sunniest April in Britain for more than sixty years.
NUM
2.
When you talk about the sixties, you are referring to numbers between 60 and 69. For example, if you are in your sixties, you are aged between 60 and 69. If the temperature is in the sixties, it is between 60 and 69 degrees.
...a lively widow in her sixties.
N-PLURAL
3.
The sixties is the decade between 1960 and 1969.
In the sixties there were the deaths of the two Kennedy brothers and Martin Luther King.
N-PLURAL: the N