Green’s Dictionary of Slang

strel n.

also strell

[Ital. strillare, to shriek]

(Polari) a banjo; thus strel/strell-homey, a banjo-player.

1984

Partridge DSUE (8th edn) 1166/2: strel(l) A banjo; hence strell-homey (or homie), a banjoist [...] late C.19–20.