auto-antonym

An auto-antonym (sometimes spelled autantonym), or contranym (originally spelled contronym), is a word with a homograph (a word of the same spelling) that is also an antonym (a word with the opposite meaning). Variant names include antagonym, Janus word (after the Roman god), enantiodrome, and self-antonym. It is a word with multiple meanings, one of which is defined as the reverse of one of its other meanings.

For example, the word "fast" can mean "moving quickly" as in "running fast," or it can mean "not moving" as in "stuck fast." To buckle can mean "to fasten" when used transitively or "to bend then break" intransitively. "To weather" can mean "to endure" (intransitive) or "to erode" (transitive). However such terms are just how one relates to the meaning of an object enduring or having endured weather, whether it is standing up against said weather unchanged, or being influenced negative by said weather, it is still either way being weathered and the additional valuation of its resultant meaning makes it an auto-anyonym only subjectively; when in actuality the word means simply how an object relates to the influence of weather for better or worse. That is an example of our perception adding meaning to the word where it may not initially imply such a meaning generally that would make it an auto-antonym. "Weedy" can mean "overgrown" ("The garden is weedy") or stunted ("The boy looks weedy"). "To overlook" can mean "to inspect" or "to fail to notice". "Strike", in baseball terms, can mean "to hit the ball" or "to miss the ball". This phenomenon is also called "enantionymy" or "antilogy."