(art, photography) Dark; characterised by dark tones and muted colours. / (by extension) Restrained, subtle, not trying to attract attention.

(Canada, US, colloquial) Kind of. / (slang) In a low-key or surreptitious manner; secretively; on the down-low.

Relaxed, unstressful, not pressured.

A restrained or subdued situation. / (photography) A dark area of a photograph with little contrast.

(informal) Alternative spelling of low-key