What does sound mean?
Sound is a versatile English word whose meaning depends on context. As a noun, it usually denotes something heard, such as a noise, voice, musical tone, or the general character of a place. It can also refer to an impression produced by speech or writing, as in statements that sound persuasive, and to an inlet or narrow sea passage. As a verb, sound means to investigate or assess something: a panel may sound out candidates, examine evidence, or test a theory. In another use, sound can signal a warning, measure depth, or pronounce a word. As an adjective, sound most commonly means healthy or in good condition, but it also means secure, reliable, and well-founded. Sound sleep is deep and uninterrupted, and sound reasoning is dependable rather than speculative. These related uses make the word especially useful when describing what is heard, what seems true, and what can be trusted.
A vibration or quality perceived by hearing, especially one produced by speech, music, or an object; also, a mental impression conveyed by speech or writing.
"The soft sound of rain against the window filled the room."
In regional British usage, sound can also mean a sea inlet or narrow passage, as in the Solent or Long Island Sound.
To investigate, test, or judge the nature, quality, or validity of something; also, to signal a warning, measure depth, or pronounce a sound.
"The committee sounded out several witnesses before reaching a decision."
The phrase sound someone out is especially common in British and American informal usage and means to try to discover their views, intentions, or abilities.
Healthy, in good condition, or free from defect; also, secure, reliable, competent, or based on sound reasoning.
"Despite the storm, the old lighthouse remained sound."
When applied to sleep, sound means deep or uninterrupted. When applied to an argument or plan, it emphasizes validity and reliability.
In a deep, complete, or uninterrupted manner, chiefly in the phrase sound asleep.
"The child was sound asleep by the time we arrived."
This adverbial use is idiomatic and normally occurs in the fixed expression sound asleep.
The plural is used for individual noises or qualities perceived by hearing and for other instances or impressions of a particular kind. It is less usual in the regional sense of a sea inlet.
"Strange sounds came from the empty room."
From a single word, English can describe a noise, the sea inlet called Long Island Sound, a healthy body, a trustworthy argument, and a deep, unbroken sleep.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of sound
The adjective meaning healthy derives from Old English gesund, a Germanic word related to forms in other Germanic languages, such as German gesund; the adjective sound also developed the senses of safe, secure, and sound in condition. The noun meaning a narrow sea passage comes from a separate Old Norse source, sund, while the verb meaning to investigate or judge ultimately relates to Old French soner and Latin sonare, associated with sounding or reporting. The common pronunciation across these senses reflects the convergence of several historically distinct words.
Related word forms
How sound is actually used
In formal writing, sound as an adjective often implies that something is well-founded and reliable rather than merely pleasing: sound reasoning, sound advice, or a sound strategy. Sound can also mean in good health, while sound asleep means deeply or completely asleep. As a noun, a body of water is generally called a sound, especially in regional names such as Long Island Sound.
Easily confused with sound
A sound is anything heard, whereas a son is a male child or descendant.