English
thiefproof
From thief + -proof.
Formed from thief + -proof
Proto-Germanic *þeubaz
Proto-West Germanic *þeub
Old English þēof
Middle English thef ‘a fraudster or con artist’
English thief
Today it means
adj secure against thieves
Sources
Sources: Wiktionary, “thiefproof”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.
Etymograph / thiefproof