FREAK
Over 70: A person with a physical deformity.
50-70: A dopehead/hippie circa 1967-1977.
Under 50: A person who likes kinky sex.
I can attest that it was at least occasionally use in that sense in Louisiana in the early 80s. It probably arose independently.
PS: In high school('73-'77), my nickname was “Freak.”
Here’s one from the UK
30-70: Liberal Democrat = The more left-wing socialist alternative to the Labour party.
Under 30:Liberal Democrat= The ultrarightwing baby-eating spawn of Thatcher
43, southwestern PA.
TMI means Three Mile Island.
GODDAMMIT! That is funny! 
Are you sure? I thought that term (re?)gained widespread popularity as a positive expression circa 1985, when the Valley Girl book (and then song) hit the stands. So, for forty-ish folks today (like me), it’s a good thing (though very rarely used at all, and when used, usually as a knowing 80s reference.)
Actually, collegiate shag is making a comeback (at least in the San Francisco swing dance world), to the great amusement of us all. So for some under-40s, it’s a dance.
I’ll throw in ‘ticked him off’ - I don’t know where the age line is, but to me that means ‘annoyed him’, while to PG Wodehouse it apparently means ‘yelled at him’.