adjective

denoting a period of time in the past that was idyllically happy and peaceful.

the halcyon days of the mid 1980s, when profits were soaring

serene,calm,pleasant,balmy,tranquil,peaceful,temperate,mild,quiet,gentle,placid,still,windless,stormless,happy,carefree,blissful,golden,joyful,joyous,contented,idyllic,palmy,flourishing,thriving,prosperous,successful

noun

a mythical bird said by ancient writers to breed in a nest floating at sea at the winter solstice, charming the wind and waves into calm.