affable (adj.)youdaoicibaDictYouDict[affable 词源字典]
late 15c., from Old French afable (14c.), from Latin affabilis "approachable, courteous, kind, friendly," literally "who can be (easily) spoken to," from affari "to speak to," from ad- "to" (see ad-) + fari "to speak," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). Related: Affably.[affable etymology, affable origin, 英语词源]
mildly (adv.)youdaoicibaDictYouDict
Old English mildelice "graciously, affably, kindly;" see mild + -ly (2). Phrase to put it mildly is attested from 1929.