sound2

adjective

• 1in good condition; not damaged, injured, or diseased:they returned safe and sound he was not of sound mind
• financially secure:she could get her business on a sound footing for the first time
• British informal excellent:He ate his lasagne with relish. ‘It’s sound, this.’

• 2based on valid reason or good judgement:sound advice for healthy living the scientific content is sound
• competent, reliable, or holding acceptable views:he’s very sound on his law

• 3(of sleep) deep and undisturbed: a doze that deepened into a sound sleep
• (of a person) tending to sleep deeply: I am a sound sleeper

• 4(of a beating) severe:such people should be given a sound thrashing

adverb

• soundly:he was sound asleep