Webster's Revised Unabridged Dictionary · 1913

Relent

Relent (r?-l?nt") , intransitive verb

[French ralentir, from Latin 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. [Obsolete]
He stirred the coals till relente gan The wax again the fire. — Chaucer
[Salt of tartar] placed in a cellar will... begin to relent. — Boyle
When opening buds salute the welcome day, And earth, relenting, feels the genial ray. — Pope
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.
Can you... behold My sighs and tears, and will not once relent? — Shakespeare

Relent , transitive verb

1.
To slacken; to abate. [Obsolete]
And oftentimes he would relent his pace. — Spenser
2.
To soften; to dissolve. [Obsolete]
3.
To mollify; to cause to be less harsh or severe. [Obsolete]

Relent (r?-l?nt") , noun

Stay; stop; delay. [Obsolete]
Nor rested till she came without relent Unto the land of Amazons. — Spenser