for auld lang syne
In honor of old times. "Auld lang syne" is a Scottish phrase meaning "old long since." Come on, you're only in town for a few days—let's go to dinner for auld lang syne.
for auld lang syne
for old times' sake. The phrase literally means ‘for old long since’, and is the title and refrain of a song by Robert Burns ( 1788 ).