Green’s Dictionary of Slang

1. to rob at gunpoint.

1928		J. Callahan Man’s Grim Justice 134: Those coons will probably try to elevate us.
1939		S.F. Examiner (CA) 27 June 13/1: Fall for the Elevation — Highway robbery conviction.
1949		Monteleone Criminal Sl. (rev. edn).

2. to hold someone up (other than for robbery).

1928

J. Callahan Man’s Grim Justice 72: If they met the coon they were to ‘elevate’ him (hold him up). [Ibid.] 90: He acted like a bull that had been elevated (stuck up) before.

3. to put up one’s hands in a hold up; thus used as imper.

1931		C. Martinez ‘Gats in the Hat’ in Gun Molls Sept. 🌐 He [...] stuck his rod into the stomach of the skinny fellow. ‘Elevate Poppy, and don’t let out a squawk.’.
1931		O. Strange Law O’ The Lariat 113: Drop that gun, shuck off yore belt, an’ elevate yore paws.
1950		Goldin et al. DAUL 65/2: Elevate. Hands up! [Note: The mark of swaggering amateurs. ‘Get ’em up’ is more common.].