From The Collaborative International Dictionary of English v.0.48:
Relent \Re*lent"\, v. t. 1. To slacken; to abate. [Obs.] [1913 Webster]
And oftentimes he would relent his pace. --Spenser. [1913 Webster]
2. To soften; to dissolve. [Obs.] [1913 Webster]
3. To mollify; to cause to be less harsh or severe. [Obs.] [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Relent \Re*lent"\ (r?-l?nt"), v. i. [imp. & p. p. Relented; p. pr. & vb. n. Relenting.] [F. ralentir, fr. L. pref. re- re- + ad to + lentus pliant, flexible, slow. See Lithe.] 1. To become less rigid or hard; to yield; to dissolve; to melt; to deliquesce. [Obs.] [1913 Webster]
He stirred the coals till relente gan The wax again the fire. --Chaucer. [1913 Webster]
[Salt of tartar] placed in a cellar will . . . begin to relent. --Boyle. [1913 Webster]
When opening buds salute the welcome day, And earth, relenting, feels the genial ray. --Pope. [1913 Webster]
2. To become less severe or intense; to become less hard, harsh, cruel, or the like; to soften in temper; to become more mild and tender; to feel compassion. [1913 Webster]
Can you . . . behold My sighs and tears, and will not once relent? --Shak. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Relent \Re*lent"\ (r?-l?nt"), n. Stay; stop; delay. [Obs.] [1913 Webster]
Nor rested till she came without relent Unto the land of Amazons. --Spenser. [1913 Webster]