Whilom (adv.) - sometimes, formerly, at times.
ffro thennes forth he rideth vp and down,
And euery thyng com hym to remembraunce
As he rood forby places of the town
In which he whilom hadde al his plesaunce.
"Lo, yonder saugh ich last my lady daunce,
And in that temple with hire eyen clere
Me kaughte first my righte lady dere.
- Chaucer, Geoffrey: Troilus and Criseyde (1385)
The Middle-English Word of the Day is selected from Mayhew and Skeat's
"Concise Dictionary of Middle English."
As found on Greg Lindahl's website
The example text was found at the Middle English Collection of the University of Virginia Library.