at one time vs whilom

at one time

prep

  • formerly 

  • simultaneously, at once. 

whilom

adv

  • At some time in the past; formerly, once upon a time. 

adj

  • At some time in the past; former, sometime. 

conj

  • During the same time that; while. 

  • Up to the time that; till, until. 

How often have the words at one time and whilom occurred in a corpus of books? (source: Google Ngram Viewer )