schnor·rer also shnor·rer 
(shnôrər)
(shnôrər)n.
Slang
Slang
One who habitually takes advantage of the generosity of others; a parasite.
[Yiddish shnorer, beggar, sponger, from shnorn, to beg, from Middle High German snurren, to hum, whir (from the sound of the musical instrument played by beggars).]