SEDA'TE, adjective [L. sedatus, from sedo, to calm or appease, that is, to set, to cause to subside.] Settled; composed; calm; quiet; tranquil; still; serene; unruffled by passion; udisturbed; as a sedate soul, mind or temper. So we say, a sedate look or countenance.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI