adjective
Definition: Based on good reasoning or judgment; reliable and valid. It can also mean being in good condition or free from defects.
Example: The engineer provided a sound solution to the problem.
adverb
Definition: In a complete or thorough manner; fully or deeply.
Example: She was sound asleep during the storm.
noun
Definition: A noise that can be heard, which can vary in pitch, volume, and quality.
Example: The sound of the waves crashing on the shore was very calming.
transitive verb
Definition: To produce or make a noise, or to express something in words; it can also mean to examine something by using sound waves.
Example: The teacher asked the students to sound the letters clearly when they read aloud.