The story
- Proto-Indo-European*(H)reh₁-
- Proto-Indo-European*(H)reh₁ís
- Proto-Italic*reis
- Classical Latinrēs
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Late Latinreālis
- Old Frenchree
- Middle Englishreal
- Proto-Indo-European*leyg-
- Proto-Germanic*līką
- Middle Englishreally
- English todayreally
From Middle English really, realy, rialliche, equivalent to real + -ly.
Etymology from Wiktionary, CC BY-SA 4.0.