Brewer's: Barbed Steed
(a corruption of barded). A horse in armour. (French, bardé, caparisoned.)
And now, instead of mounting barbëd steeds To fright the souls of fearful adversaries, He capers nimbly in a lady's chamber, To the lascivious pleasing of a lute.
Shakespeare: Richard III, act i. 1.;
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894