fif‧ty /ˈfɪfti/ number, noun
[Language: Old English; Origin: fiftig, from fif 'five']

1. the number 50

2. the fifties [plural] (also the '50s, the 1950s) the years between 1950 and 1959:
Standards of living rose in the fifties.
the early/mid/late fifties
The play was written in the late fifties.

3. be in your fifties to be aged between 50 and 59
early/mid/late fifties
He must be in his early fifties by now.

4. in the fifties if the temperature is in the fifties, it is between 50 degrees and 59 degrees
in the low/mid/high fifties
sunny, with temperatures in the mid fifties

5. [countable] a piece of paper money that is worth 50 dollars or 50 pounds:
I can give you five tens for that fifty if you want.
—fiftieth adjective:
her fiftieth birthday

[TahlilGaran] Dictionary of Contemporary English ▲