The story
- Proto-West Germanic · inherited from*sanþafast
- Old English · inherited fromsōþfæst“true, trustworthy”
- Middle English · inherited fromsothfast
- English todaysoothfast
From Middle English sothfast, from Old English sōþfæst (“true, trustworthy”), from Proto-West Germanic *sanþafast. Equivalent to sooth + fast.
Words from the same roots
Old Englishsōþfæst all →
honest
Etymology from Wiktionary, CC BY-SA 4.0.