Definition of "eterne"

The substance is eterne, and bideth so; / Ne when the life decayes and forme does fade, / Doth it consume and into nothing goe [...].

1590, Edmund Spenser, “Book III, Canto VI”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie

And neuer did the Cyclops hammers fall / On Mars his Armours, forg'd for proofe Eterne, / With lesse remorse then Pyrrhus bleeding sword / Now falles on Priam.

c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene ii]

Eterne, intense, profuse,—still throwing upThe golden spray of multitudinous worldsIn measure to the proclive weight and rushOf His inner nature […]

1856, Elizabeth Barrett Browning, “Third Book”, in Aurora Leigh, London: Chapman and Hall, […], published 1857