1. (a.) Calm; pertaining to, the halcyon, a fabled bird which was said to calm the waves\, laying her eggs in nests on or near the sea during the calm weather about the winter solstice.

2. (n.) A kingfisher. By modern ornithologists restricted to a genus including a limited number of species having omnivorous habits, as the sacred kingfisher (Halcyon sancta) of Australia.

3. (a.) Hence: Calm; quiet; peaceful; undisturbed; happy.

Saturnian at peace at rest balmy bloodless blooming blossoming booming bright calm clear cloistered concordant cool dwindling ebbing even-tenored exuberant fair fat flourishing flowering fruiting going strong hushed idyllic impassive in full swing in good case isolated mild moldering orderly pacific palmy pastoral peaceable peaceful peacetime piping placid prospering quiescent quiet reposeful reposing restful resting rosy secluded sequestered sequestrated serene sheltered sleek smooth soft still still as death stillish stilly stoic stolid subsiding sunny thriving tranquil unagitated undisturbed unmoved unperturbed unruffled unstirring untroubled vigorous waning