Definition of "dastard"

I thought ye would never have given out these arms till you had recovered your ancient freedom: but you are all recreants and dastards, and delight to live in slavery to the nobility.

1591 (date written), William Shakespeare, “The Second Part of Henry the Sixt, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies. […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act IV, scene viii]

The dastard, that did heare him selfe defyde, / Seem'd not to weigh his threatfull words at all, / But laught them out, as if his greater pryde, / Did scorne the challenge of so base a thrall: Or had not courage, or else had no gall.

1596, Edmund Spenser, “Book VI, Canto III”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, page 36

My client, an innately bashful man, would be the last man in the world to do anything ungentlemanly which injured modesty could object to or cast a stone at a girl who took the wrong turning when some dastard, responsible for her condition, had worked his own sweet will on her.

1922 February, James Joyce, Ulysses, Paris: Shakespeare and Company, […]

Like dastard Curres, that having at a bay / The salvage beast embost in wearie chace, / Dare not adventure on the stubborne pray, / Ne byte before, but rome from place to place, / To get a snatch, when turned is his face.

1590, Edmund Spenser, The Faerie Queene, Book III, Canto One, Stanza 22, in The Faerie Queene, Books Three and Four, edited by Dorothy Stephens, Hackett, 2006, p. 13

Now dragg'd once more beyond the western main, To groan beneath some dastard planter’s chain;Where my poor countrymen in bondage waitThe long enfranchisement of ling’ring fate:

1789, Olaudah Equiano, chapter 5, in The Interesting Narrative of the Life of Olaudah Equiano‎

Observe, too, that this is all a modern affair; belongs not to the old heroic times, but to these dastard new times. ‘Happiness our being’s end and aim’ is at bottom, if we will count well, not yet two centuries old in the world.

1843 April, Thomas Carlyle, “ch. IV, Happy”, in Past and Present, American edition, Boston, Mass.: Charles C[offin] Little and James Brown, published 1843, book III (The Modern Worker)

Would my short life had yet a shorter date! / I'm weary of this flesh which holds us here, / And dastards manly souls with hope and fear; / These heats and colds still in our breast make war, / Agues and fevers all our passions are.

1665, John Dryden, The Indian Emperour, or the Conquest of Mexico by the Spaniards, being the Sequel of The Indian Queen, Act II, Scene 1