Some popular slang used by youngsters in 1965.
Bad- mean tough
Bent- grouchy
Down the tubes- in trouble, bad condition
Fuzz- policeman
Groovy- great, wonderful, good
Hangin'- huge, enormous
Hang-up- bother or nuisance
Hero- strong man or show off
Hood- juvenile delinquent
Man- an expression of feeling with no real meaning
Neat- better than average, good, great
Old Lady- mother
Old Man- father
Out of it- naive, not keeping up with the times
Pad- house or apartment
Pipe down- be quiet
Riot- something spectacular
Shades- sunglasses
Slick- good, great, best
Split- to leave, go away
Swingin'- really good
Thick- naive, dense, dumb
Tuff- good, great, best
Threads- clothes
Weirdo- an odd strange, or peculiar person

http://www.cougartown.com/slang-dict6.html