Halcyon (adj)
hal-see-on
Denoting a period of time in the past that was idyllically happy and peaceful.
Late Middle English (in the mythological sense): via Latin from Greek alkuōn ‘kingfisher’ (also halkuōn, by association with hals ‘sea’ and kuōn ‘conceiving’).
Example sentences
“Ah the halcyon days of our youth.”