Green’s Dictionary of Slang

extremely good, first-rate, splendid.

1762		Gent.’s Mag. 86/2: Here’s cream — damn’d fine — immense — upon my word!
1772		G. Stevens ‘Time Killers’ in Songs Comic and Satyrical 216: Dear Bragg, Hazard, Loo, and Quadrille, / Delightful! extatic! immense!
1850		Fast Man 7:1 n.p.: [T]he fun they had, take it all in all, [was] immense.
1879		Cincinnati Enquirer 7 Sept. 10/7: Immense – Any thing or any body that is good is immense, as well as a big house or a large person.
1880		Bulletin (Sydney) 7 Feb. 6/1: Tottles’ assumption of refined elegance, with a sort of lardidaism is ‘immence,’ [sic] but nothing can exceed his reproof of Bung for his vulgarisms and mispronunciation.
1889		Music Hall & Theatre Rev. 16 Feb. 4/2: De Voy, Leclerq, and Co. were just finishing their amusing nigger business. These artistes are ‘immense,’ and a sure card for any manager.
1890		‘’Arry on Equality’ in Punch 22 Feb. 85/2: When Science and Saintship shake hands, in a sperret of sound common sense, / To chuck over the cant of the Pulpit, by Jingo, old pal, it’s Himmense!
1892		H.J. Sayers [perf. Lottie Collins] Ta-ra-ra Boom-de-ay 🎵 Pa says that I have no sense / [...] But men say that I’m just immense.
1894		Coburg Leader (Vic.) 17 Nov. 2/7: Billy on the bones is simply immense.
1902		C.L. Cullen More Ex-Tank Tales 107: You’re looking immense.
1908		B. Fisher A. Mutt in Blackbeard Compilation (1977) 54: ‘Now the boobyhatch have formed a reception club called “Daffy with dormant domes” and —’ ‘Immense, general.’.
1913		Van Loan ‘The Mexican Marvel’ in Lucky Seventh (2004) 189: Bo, you’re immense! Immense!
1914		349A. Brazil Leader of the Lower School 39: ‘Awfully pretty, I call her [...] Those big red bows are immense in more ways than one’.
1922		Joyce Ulysses 88: - Tom Kernan was immense last night, he said.
1923		H.C. Witwer Fighting Blood 112: That bathrobe is immense.
1938		D. Runyon ‘Madame La Gimp’ in Runyon on Broadway (1954) 249: The old judge looks immense in his swallowtail coat.