refers to an older woman in 'younger' clothing; looks 16 from the back, but 61 from the front.
Ew, how 1661 is she?
by ...<@!+Y March 19, 2007
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A bird that looks young and fit from behind, but when you see the front she is old and ugly.
Driver: Look at the fit arse on that bird.
Passenger (as passes in front): Unlucky mate, she's a 1661.
by Bookim Danno October 1, 2006
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