1.  To assent to as true. Testament of Love. [1913 Webster]

2.  To assent to; to comply with; to gratify; to humor by compliance; to please with blandishments or soft words; to flatter. [1913 Webster]
"Good, my lord, soothe him, let him take the fellow." [1913 Webster]
"I've tried the force of every reason on him,
Soothed and caressed, been angry, soothed again." [1913 Webster]

3.  To assuage; to mollify; to calm; to comfort; as, to soothe a crying child; to soothe one's sorrows. [1913 Webster]
"Music hath charms to soothe the savage breast,
To soften rocks, or bend a knotted oak." [1913 Webster]
"Though the sound of Fame
May for a moment soothe, it can not slake
The fever of vain longing." [1913 Webster]

soothe, v.tr.
1 calm (a person or feelings).
2 soften or mitigate (pain).
3 archaic flatter or humour.

Derivative:
soother n. soothing adj. soothingly adv.

Etymology:
OE sothian verify f. soth true: see SOOTH

VB  be moderate, keep within bounds, keep within compass, sober down, settle down, keep the peace, remit, relent, take in sail, moderate, soften, mitigate, temper, accoy, attemper, contemper, mollify, lenify, dulcify, dull, take off the edge, blunt, obtund, sheathe, subdue, chasten, sober down, tone down, smooth down, weaken, lessen, check palliate, tranquilize, pacify, assuage, appease, swag, lull, soothe, compose, still, calm, calm down, cool, quiet, hush, quell, sober, pacify, tame, damp, lay, allay, rebate, slacken, smooth, alleviate, rock to sleep, deaden, smooth, throw cold water on, throw a wet blanket over, turn off, slake, curb, tame, smooth over, pour oil on the waves, pour oil on the troubled waters, pour balm into, mattre de l'eau dans son vin, go out like a lamb, roar you as gently as any sucking dove.

VB  relieve, ease, alleviate, mitigate, palliate, soothe, salve, soften, soften down, foment, stupe, poultice, assuage, allay, cheer, comfort, console, enliven, encourage, bear up, pat on the back, give comfort, set at ease, gladden the heart, cheer the heart, inspirit, invigorate, remedy, cure, refresh, pour balm into, pour oil on, smooth the ruffled brow of care, temper the wind to the shorn lamb, lay the flattering unction to one's soul, disburden, take a load off one's chest, get a load off one's chest, take off a load of care, be relieved, breathe more freely, draw a long breath, take comfort, dry the tears, dry the eyes, wipe the tears, wipe the eyes.

VB  flatter, praise to the skies, puff, wheedle, cajole, glaver, coax, fawn upon, faun upon, humor, gloze, soothe, pet, coquet, slaver, butter, jolly, bespatter, beslubber, beplaster, beslaver, lay it on thick, overpraise, earwig, cog, collogue, truckle to, pander to, pandar to, suck up to, kiss the ass of, pay court to, court, creep into the good graces of, curry favor with, hang on the sleeve of, fool to the top of one's bent, lick the dust, lay the flattering unction to one's soul, gild the pill, make things pleasant, overestimate, exaggerate.