A snarling, churlish person, like a cynic. The cynics were so called because Antisthenes held his school in the gymnasium called Cynosarges, set apart for those who were not of pure Athenian blood. Cynosarges means white dog, and was so called because a white dog once carried away part of a victim which Diomeos was offering to Hercules. The sect was often called the Dog-sect; and the effigy over Diogenes' pillar was a dog, with this inscription:
“Say, dog, I pray, what guard you in that tomb?”
“A dog.”—“His name?”—“Diogenes.”—“From far?”
“Sinope”—“What! who made a tub his home?”
“The same; now dead, amongst the stars a star.”
“[They] fetch their doctrines from the Cynic tub.”
Milton: Comus, line 708.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894