auld lang syne 
/ˌoʊldˌlæŋˈzaɪn/ noun
/ˌoʊldˌlæŋˈzaɪn/ noun [singular] : the good old times
▪ They drank a toast to auld lang syne. ◊Auld lang syne comes from the name of a Scottish song that is traditionally sung at midnight on New Year's Eve.
▪ They drank a toast to auld lang syne. ◊Auld lang syne comes from the name of a Scottish song that is traditionally sung at midnight on New Year's Eve.
