sixties

noun[plural only]2

1. •
   The decade of one's life from age 60 through age 69.

   • She retired at some point in her sixties, I don't recall exactly when.
2. •
   The range between 60 and 69 Fahrenheit.

   • Highs in the mid sixties.

adjective1

1. •
   From or evoking the 61st through 70th years of a century (chiefly the 1960s).

   • She coughed as she exhaled. Sixties weed had been nowhere near this strong.

noun[plural only]2

1. •
   The decade of the 1860s, 1960s, etc. (but especially the 1960s)

   • Occasionally this was a direct result of network attitudes — as in the fifties with integration, the sixties with Vietnam, or the seventies with Watergate. — 1981
2. •
   A period in American history centered around the counterculture movement of the late 1960s.

   • The 1960s and the first half of the 1970s—an era known as "the sixties" to most observers—has perhaps generated more mythology than any other period in American history. — 1999