English

Noun

mad-dog ‎(plural mad-dogs)

1. Mad dog when used as an attributive noun
   • 1970, J. Spencer Grendahl, The mad dog press archives: a novel, page 105:

     These are mad-dog times, man!

   • 2014, Collin Wilcox, Night Games, ISBN 1784089109:

     Then she calls the cops, reports your standard mad-dog black burglar.

   • 2014, William W. Johnstone, Tyranny in the Ashes, ISBN 1497630649:

     All we have to do is kill the mad-dog Nicaraguan who oppresses our people, calling himself a soldier.

   • 2014, Don Pendleton, Detroit Deathwatch, ISBN 1497685710:

     And, now, these same cynical cops were being asked to shoot that dude on sight, to treat him like a mad-dog psychopath—the sanest guy in town.

2. (rare) Alternative form of mad dog
   • 1839, Thomas Wright, An Essay on the State of Literature and Learning Under the Anglo-Saxons, page 99:

     Against the bite of a mad-dog : take two onions or three, boil them, spread them in ashes, mix them with fat and honey, lay it on.

   • 2012, Dr. B. R. Suhas & ‎Prof. L. S. Seshagiri Rao, Louis Pasteur, ISBN 812801787X:

     To detect the microbes, he had to collect the saliva of a mad-dog.

   • 2013, J. B. Sidgwick, The Shorter Poems of Walter Savage Landor, ISBN 1107635217, page 89:

     Like mad-dog in the hottest day Byron runs snapping strait away, And those unlucky fellows judge ill Who go without a whip or cudgel.

   • 2015 November 23, James Butty, “Nigeria's Military Vows to Destroy Boko Haram as Attacks Continue”, in Voice of America:

     It's also a proof that the newly appointed mad-dogs may be the same bad-eggs of the system that squandered the defense budget, sided with the insurgents and fought the country.

Adjective

mad-dog ‎(comparative more mad-dog, superlative most mad-dog)

1. Fanatically or irrationally ferocious.
   • 1908, The Spectator - Volume 100, page 748:

     It takes a professor to arrive at so mad-dog a state of mind.

   • 1975, J. M. Barrie, Peter Pan in Kensington Gardens, ISBN 9633818354:

     In the Broad Walk you meet all the people who are worth knowing, and there is usually a grown-up with them to prevent them going on the damp grass, and to make them stand disgraced at the corner of a seat if they have been mad-dog or Mary-Annish.

   • 2011, Les Standiford, Havana Run: A John Deal Mystery, ISBN 1615953086:

     You probably never heard of Mr. Dobbins, since it looks like you live in some other dimension, but Dobbins happens to be the most mad-dog, publicity-hungry attorney to walk the planet.

Usage notes

It can be difficult to distinguish between the standard practice of inserting a hyphen into a noun phrase when it is used attributively (that is, using mad-dog for the noun phrase mad dog) and the use of this term as a genuine adjective. There is evidence that this form is sometimes used as a genuine adjective, as can be seen in the quotations. However, the most common usage is as an attributive noun.