Green’s Dictionary of Slang

1. to leave.

1899–1900		C.L. Cullen Tales of the Ex-Tanks 310: We faded out into the nippy, frosty street.
1931		O. Strange Law O’ The Lariat 41: I just fade out, leavin’ no word, an’ yu take hold an’ run the ranch.
1933		Ersine Und. and Prison Sl.
1937		P. Cheyney Dames Don’t Care (1960) 14: Fade out for the border by car.
1950		Goldin et al. DAUL 67/1: Fade out, v. To slip away unobtrusively.
1956		R.T. Hopkins Banker Tells All 32: Some, a few of them bank clerks and officials, ‘fade out’ with money which does not belong to them.
1959		E. De Roo Go, Man, Go! 75: OK, Flash, since you really go for one another, I’ll fade out of the picture.
2000		(con. 1940s–60s) Décharné Straight from the Fridge Dad.

2. to die.

1875		J.H. Warren Crying Shame of NY 191: [They] faded out with the malady that came to them as an inheritance from both the paternal and maternal side.
1949		Monteleone Criminal Sl. (rev. edn).
1981		S. Berkoff Decadence in Decadence and Other Plays (1985) 36: My hate’s not hot enough / to shove a knife in this ponce’s gut / I’ll let him fade out like the dinosaur.