A continuation of the series
1. Former; erstwhile
1. At one time
According to Etymonline.com:The definition "at time past" is considered archaic and dates to the 1200's. It comes from Old English hwilum ("at times"), which is the dative case of while.
And whilom at it, I may as well mention Mighty Red Pen's recent post titled Erstwhile, back at the ranch. Check it out here.
Definition from Lovely Little Lexemes