Green’s Dictionary of Slang

slicer n.

(US black/Und.) a knife.

[US]Monteleone Criminal Sl. (rev. edn).
[US]E. Folb Runnin’ Down Some Lines 254: slicer Knife.
[UK]J. Cameron Hell on Hoe Street 223: You want your brother beside you, be there with his slicer.