Proofed

Part of speech: verb

Pronunciation: /pɹuːft/

Definitions

1. Shown or demonstrated to be true or valid ; treated or prepared to resist damage, spoilage, or penetration
2. Produced evidence that establishes certainty or correctness ; made durable or protected against harm or decay
3. Supplied validation or confirmation of accuracy ; processed to ensure strength or protection from elements

Etymology: "Proofed" is the past tense and past participle of "proof," used as a verb meaning to make something resistant to a substance, most often water. Its own sense of "shown to be true" is the one the question asks about, but the verb form here traces back through the noun. The noun "proof" came into Middle English from Old French "prove," which descends from Late Latin "proba," meaning "a proof," itself from Latin "probare," to test or prove. The Latin verb meant to test, approve, or demonstrate, and that idea of testing is still carried in the word. A proof is a test that something holds up, and making a thing proof against water or fire means it has passed that test in advance. English also kept a close relative, "probe," which entered the language as a doublet of "prove," so the two words share a single Latin ancestor despite their different forms.