SOUND'LY, adverb [from sound, entire.] 1. Healthily; heartily. 2. Severely; lustily; with heavy blows; smartly; as, to beat one soundly 3. Truly; without fallacy or error; as, to judge or reason soundly 4. Firmly; as a doctrine soundly settled. 5. Fast; closely; so as not to be easily awakened; as, to sleep soundly
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI