Origin and history of infer

1610s, "stating or introducing an inference" (of words such as because, then, therefore); 1630s, "inferential, arising from inference," from Late Latin illativus, from Latin illatus "brought in," used as past participle of inferre "to bring in, introduce" (see infer). Grammatical sense "case expressing motion into" is from 1890. As a noun from 1590s, "illative word." Related: Illation "action of inferring" (1530s).

late 14c., implien, emplien "to enfold, enwrap, entangle" (the classical Latin sense), from Old French emplier, from Latin implicare "involve, enfold, entangle," from assimilated form of in- "into, in, on, upon" (from PIE root *en "in") + plicare "to fold" (from PIE root *plek- "to plait").

Meaning "to involve something unstated as a logical consequence" first recorded c. 1400; that of "to hint at" is from 1580s. Related: Implied; implying. The distinction between imply and infer is in "What do you imply by that remark?" but, "What am I to infer from that remark?" Or, as Century Dictionary puts it, "An action implies ability or preparation, but involves consequences."