allegedly vs soi-disant

allegedly

adv

  • According to someone's allegation. 

  • According to someone's conspicuous impressions (which could subsequently be alleged). 

soi-disant

adv

  • supposedly 

adj

  • Self-styled; self-proclaimed. 

How often have the words allegedly and soi-disant occurred in a corpus of books? (source: Google Ngram Viewer )