The story
- Proto-Indo-European*súHros
- Proto-Germanic*sūraz
- Proto-West Germanic*sūr
- Old Englishsūr
- Middle Englishsour
- Middle Englishsourisch
- English todaysourish
From Middle English sourisch, sourissh, sowrische, sowrishe, sowrisshe, sowryssh; equivalent to sour + -ish.
Etymology from Wiktionary, CC BY-SA 4.0.