unruffled

Not agitated emotionally; calm.

Not disordered or disturbed physically.

Calm; tranquil; not agitated; not disturbed: as, an unruffled temper.

Not ruffled or agitated; smooth; calm; tranquil; quiet.

Calm, not ruffled, serene, at peace, unbothered.

(of a body of water) free from disturbance by heavy waves

free from emotional agitation or nervous tension