Green’s Dictionary of Slang

awesome adj.

[weak use of SE; the term gained a new currency, esp. among the pre-teens, with the popularity c.1990 of the cartoon/film heroes Teenage Mutant Ninja Turtles, in whose dialogue it featured heavily]

1. (also awes) impressive, enormous, frightening.

[[Scot]J. Hogg Brownie of Bodsbeck I 280: ‘It is his ghaist come to haunt the place.’ [...] ‘Ower true! it’s awesome to think o’’].
[US]H.C. Witwer Kid Scanlon 268: I wish I had a line of patter like that! Amazin’ and awesome accuracy!
[US]G. Cuomo Among Thieves 339: It’s too awesome even to contemplate.
[US]R. Sabbag Snowblind (1978) 174: Awesome. Blood and raw meat.
[US]G. Tate Flyboy in the Buttermilk (1992) 37: The tapes from that concert [...] are awesome. It’s like funk on the Ellingtonian or symphonic level.
[US]J. Wambaugh Golden Orange (1991) 172: The harbor jetty [...] was jammed with kids daring the reeeelyawesome waves that sometimes roar to twelve feet.
[UK]N. Barlay Curvy Lovebox 63: Almost gettin mashed by the awesome eighteen wheeler pullin’ out of a concealed entrance.
[UK]Observer Mag. 25 Jan. 28: It were awesome. The best rock’n’roll show I’ve seen since Motorhead seven years ago.
[UK]N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 224: They were awesome fist-fighters.
[SA]IOL News 9 Nov. 🌐 Cape Town’s scenery is awesome.

2. (orig. US teen) wonderful, excellent, the best.

[US]Eble Campus Sl. Mar. 1: awesome – fantastic.
[US]‘Victoria Parker’ Incest Schoolgirls 🌐 ‘Oooooh,’ she whispered. ‘That would be totally awesome!’.
[US]D. Clowes Ghost World 39: Check out that waiter’s awesome ‘fifties’ hair-do!
[UK]Guardian Guide 1–6 Jan. 18: Went to see Stretch’n’Vern [...] which was awesome.
[UK]L. Theroux Call of the Weird (2006) 129: Mike is awesome. Very open-minded.
[UK]Times Mag. 30 Apr. 96/3: ‘That is so awesome,’ said my son, cackling wildly.
[US]S. King Finders Keepers (2016) 89: He thought the Young Lions was fucking awesome.
[Aus]G. Gilmore Base Nature [ebook] ‘I’ve got some awesome news’.

In derivatives

awesomesauce (adj.)

(US) epitomizing excellence; also as excl. of approbation [underpinned by brand name of cleaning product Awesome Sauce]. 22 Sept. [Usenet group] 🌐 You guys are awesomesauce.
Urban Dict. 8 June 🌐 awesome sauce a beautifully assonant phrase which can and should be used on any occasion where joy and elation are expressed.
[US]C. Eble UNC-CH Campus Sl. Spring 2016 1: AWESOMESAUCE - excellent: X: ‘I’ll have this project done by tomorrow.’ Y: ‘Awesomesauce.’.