sound.
Decent, reliable, friendly, or good. As a short reply, “sound” can mean “okay,” “agreed,” or an appreciative acknowledgment.
What does sound mean?
Calling someone sound is usually a compliment to how they behave: they seem decent, reliable, or easy to deal with. It does not refer to their voice. Calling a plan sound may mean it is good or acceptable, with overlap between informal approval and the standard sense of sensible or well-founded.
As a stand-alone reply, sound can acknowledge an arrangement or express thanks. “I will leave it at reception.” — “Sound.” is a brief, friendly acceptance in a familiar context. Delivery still matters, and a different topic can activate ordinary meanings such as noise, healthy condition, or a sound argument.
See how it lands.
Original examples written for this entry, not quotations from the sources.
She waited with me until the bus came. She is sound.
“I saved you a seat.” “Sound, thanks.”
The right word.
The right moment.
Use it for informal approval or a friendly response where the regional sense fits. Specific behavior makes a compliment more meaningful.
Avoid translating every sound as noise. In formal reasoning, a sound argument is well-founded or valid in a technical sense, not simply a friendly person.
Not quite the same as…
sound advice
This is standard English for good, reliable advice. It overlaps with but does not depend on the regional slang use.
Across the Atlantic
Decent or reliable is often the right reading for a person; okay or thanks may fit a brief reply. Local frequency varies.
A little backstory.
The approving sense develops alongside older meanings of sound such as healthy, secure, or reliable. Wiktionary documents the UK and Irish informal adjective and response.
Supported by Wiktionary contributors
Still wondering?
Is calling someone sound a compliment?
Usually yes. It suggests they are decent, reliable, or good company.
Can sound mean thank you?
In an informal short response it can express appreciative agreement, depending on the exchange and local usage.
Sources & checks
Meaning and factual notes are informed by the references below. Examples and usage advice are original editorial writing. A source documents use; it does not measure current popularity.
- sound — English entry ↗Wiktionary contributors · checked 19 Oct 2026Supports: meaning; usage