Definition of "cur"

A fals double tunge is more fiers and fellThen Cerberus the cur couching in the kenel of hel;Wherof hereafter, I thinke for to write,Of fals double tunges in the diſpite.

c. 1515–1516, published 1568, John Skelton, Againſt venemous tongues enpoyſoned with ſclaunder and falſe detractions &c.

you have many enemies, that know not why they are so, but, like to village-curs, bark when their fellows do.

1613 (date written), William Shakespeare, [John Fletcher], “The Famous History of the Life of King Henry the Eight”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iv]

Makola, a civilized nigger, was very neat in his person. He threw the soapsuds skilfully over a wretched little yellow cur he had, then turning his face to the agent's house, he shouted from the distance, "All the men gone last night!"

1897, Joseph Conrad, “II”, in An Outpost of Progress

"You have no more spirit than a mongrel cur. You lie down on the ground and ask people to trample on you."

1919, W[illiam] Somerset Maugham, “chapter 25”, in The Moon and Sixpence, [New York, N.Y.]: Grosset & Dunlap Publishers […]

This butcher's cur is venom-mouth'd, and I have not the power to muzzle him.

1613 (date written), William Shakespeare, [John Fletcher], “The Famous History of the Life of King Henry the Eight”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene i]

"Who 's a cur - now - hey?"

1900, Joseph Conrad, Lord Jim, page vi. 54