From Longman Dictionary of Contemporary Englishhalcyonhal‧cy‧on /ˈhælsiən/ adjective → halcyon days
Examples from the Corpus
halcyon• For a time the halcyon days of 1825 returned.Origin halcyon (1500-1600) halcyon “bird believed to bring good weather at sea” ((14-19 centuries)), from Latin, from Greek alkyon “kingfisher” 