of which there is no possible doubt

confident

pleasant to be in or on

good feeling

gentle; not severe

gentle, temperate, non-irritating

limited; (of an opinion, a desire, feelings etc) in the middle within reasonable limits

calm, temperate

having or showing no interest or enthusiasm

easy-going, laid back

preferring or enjoying, peace; calm; quiet

friendly, serene

still and quiet; giving (a feeling of) rest

quiet

happy and calm

calm, undisturbed

(of surface) level or polished, like glass; calm and free from uncomfortable movement; (of a liquid mixture) free from lumps

level, unwrinkled; flowing

without movement or sound; not having bubbles; (of an action, situation) continuing as in the past; a quiet and calm atmosphere

calm, motionless, quiet

calm; quiet

quiet, peaceful

(e.g. of a horse) not tamed; not interrupted; (of a record etc) not beaten

continuous, whole

not anxious (about); not (emotionally) concerned (with)

carefree; apathetic