[1] : The Collaborative International Dictionary of English v.0.48

whilom \whi"lom\ hwimac"lu^m, adv. as. hwimaclum,
   properly, at times, dative pl. of hwimacl; akin to g.
   weiland formerly, ohg. hwimacl=om, see while, n.
   formerly; once; of old; erewhile; at times. obs. or poetic
   --spenser.
   1913 webster

         whilom, as olde stories tellen us,
         there was a duke that highte theseus.    --chaucer.
   1913 webster
see also:
while 

Whilom >> W Words
Whilom, definition of term: Whilom
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