Auto-antonym
A Janus word ( after the god Janus, also Autoantonym ) is a word with at least two meanings, one meaning is the opposite of another ( "auto- antonymy "). Janus words relate to each other at the same time (having an opposite meaning) antonym and homonym ( same sounding ).
The complementary phenomenon is the (eg by Desemantisierung related ) homonymy actually antonymer words such as, without that change, for example in practice and in theory, are in colloquialisms as you can, omit virtually interchangeable, the sentence meaning: the you can omit theoretically.
Designations
The linguist Andreas Blank speaks of Autoantonymie. The names Antagonym and Kontranym are in the German language new loan translations and rare.
The English name antagonym was invented by Charles N. Ellis, who maintains a list of English Janus words on the internet. The term auto- antonymy was proposed in 1994 by Alex Berg owls.
Occurrence
In practice, Janus words occur because of their ambiguity rarely occurs. In English, they are somewhat more common than in English. Formation they can change in meaning ( polysemy ) or phonetic ( homophony ) or written collapse ( homography ) of different words.
Most will by the sentence context, the intended meaning clear, sometimes even by the linguistic variety. For example, the word shoal in the nautical for a very small depth (un - negation ), outside the seafaring but for a very large ( immeasurable ) Depth ( Augmentativbildung with un - ). In other cases, apparent Janus words differ in the word accent (Detour - Detour) or are syntactically or limited as regards the thematic role of their reference words ( eg, transitive / intransitive stop to stop un-/belebtes object).