Etymology Dictionary

SOOTHE,  to please with gentle words or flattery, to flatter, appease.  (E.)   The orig. sense is 'to assent to as being true,' hence to say yes to, to humor by assenting, and generally to humor.  'Sooth, to flatter immoderatelie, or hold vp one in his talke, and affirme it to be true, which he speaketh;' Baret (1580).   'Is't good to soothe him in these contraries?'  Com. of Errors, iv. 4. 82.   'Soothing the humor of fantastic wits;' Venus and Adonis, 850.   Cf. the expression 'words of sooth,' Rich. II, iii. 3. 136.   M. E. soðien, to confirm, verify; whence isoðet, confirmed, O. Eng. Homilies, i. 261, l. 8.—A. S. ge-sóðian (where the prefix ge- makes no difference), to prove to be true, confirm; Dooms of Edward and Gunthrum, sect. 6, in Thorpe's Ancient Laws, i. 170.   Cf. A. S. gesóð, a parasite, flatterer, in a gloss (Bosworth).—A. S. sóð, true; see Sooth.   Cognate verbs occur in the Icel. sanna, Dan. sande, to verify, confirm. [†]

ADDENDA

'That's as much as to say you would tell a monstrous... lie, and I shall sooth it,' i.e. I am to bear witness to its truth; Faire Em, Act. iii. sc. 11; in Simpson's School of Shakespeare, ii. 443, l. 866.   'What better way than this?  To sooth his purpose and to draw him on With expectation;' Play of Stucley, l. 1516; id. i. 219.