late 13c., from Old French forclos, past participle of forclore "exclude, shut out; shun; drive away" (12c.), from fors "out" (Modern French hors; from Latin foris "outside;" see foreign) + clore "to shut" (see close (v.)). Senses in English influenced by words in for- (which is partly synonymous with the Latin word) and spelling by a mistaken association with native fore-. Specific mortgage law sense is first attested 1728. Other Middle English for- words in which the same prefix figures include forjuggen "condemn, convict, banish;" forloinen "forsake, stray from," and forfeit. Related: Foreclosed; foreclosing.