The story
- Proto-Indo-European*dʰeyǵʰ-
- Proto-Indo-European*dʰinéǵʰti
- Proto-Italic*θingō
- Proto-Italic*fingō
- Latinfingō
- Latinfictus
- Latinfictīcius
- Englishfictitious
- Proto-Indo-European*leyg-
- Proto-Germanic*līką
- English todayfictitiously
From fictitious + -ly.
Etymology from Wiktionary, CC BY-SA 4.0.