I’m trying to entertain (and possibly even educate!) my students by coming up with a list of slang words that have been used as synonyms for “cool” over the past decades and centuries.
Right now I’ve got:
spiffy - 1940’s?
swell - 1950’s?
nifty - 1980’s?
radical - 1980’s?
neat - 1990’s?
cool - current
I know “cool” is current because my students use it. The rest of the dates are basically guesses, because I sure don’t remember (and I still use half of them, too).
Anybody have any more?
'60s - Boss
'70s- Righteous
and I think the current term is “kewl”. You have to say it with a certain California valley-speak accent.
I have no cites, but I’m pretty sure that “cool” has been around for quite some time. Yes it’s still current, but it dates from at least the '50s (I think). I also believe that “nifty” and “neat” have been around since the '50s, too. Again, no cites, just what I remember from books/magazines/tv shows.
A couple more from the ‘80s are "bitchin’" and “tripendicular.”
From the '90s, we have “tight.”
So it has a bit of a history.
If Stan Freberg and my father are to be believed, the phrase “real george” was around in the 50’s. I can’t find anything on Google, though.
From growing up in the 80’s:
wicked, awesome, radical, bad
The OED’s earliest citation for cool in this sense is from 1948:
Awesome went over into the 90s too.
Napoleon Dynamite gave us ‘sweet.’
The '60’s gave us “groovy”, the '70’s “uptight” and “outta sight”.
phat, tight, bitchin
actually I think “nifty” is earlier - 1950’s perhaps,
and “spiffy” is 1960’s
“cool” is perennial - it was used as far back as the 40’s, possibly the 30’s.
“neat” is definitely 1960’s
I’ll add
late 90’s: FABulous (with the “FAB” part being said in a high squeaky voice and the rest normally)
mid to late 60’s: “fabu”
Michael Jackson gave us “bad.” “Far out” was used a lot…
“Tubular” and “Totally Tubular” were used in the 80’s after they were made known in a few movies and a song. Odd ones. I sure they were rare.
Strange uses of the phrase on the web.
Jim
“Radical” fits in somewhere.
Hate to correct spelling, but it’s “schweeeet”. 
I heard “sweet” way before I saw Napoleon Dynamite. I’d say it’s at least as old as '90s.
And “swell” goes back to at least the '20s.
Not very widely used by people who aren’t Firefly geeks, but I think “shiny” should be the new “cool”. Who’s with me?!
crickets
gnarly
::raises hand:: I heard “shiny” in a non-Firefly context on TV a few days ago, but I’m damned if I can remember the show.
Where would hunky dory fit? 40’s?
Don’t forget:
-Slamin’
-Kickin’
-Bad-ass
I always thought of “hunky dory” as meaning “ok” or “fine,” not “cool.”
“How are things going?”
“Everything’s hunky dory.”
I can’t imagine anyone saying “Did you see that car? It’s hunky dory!”
The advent of hip hop brought us “dope,” “fly,” “fresh,” “stupid,” “stupid fresh,” “the shit,” “the bomb,” (actually a Parliamentism from the '70s,) “the shizzle,” etc. I’m sure I’m missing 700 or 800 of them.