An autological word (also called homological word) is a word expressing a property which it also possesses itself (the word "short" is short, "common" is common, "noun" is a noun, "English" is English, "pentasyllabic" has five syllables, "word" is a word). The opposite is heterological, a word that does not apply to itself ("long" is not long, "banana" is not a banana, "Englisch" is German). A number of autological words are available at this website.
Unlike more general concepts of autology and self-reference, this particular distinction and opposition of "autological" and "heterological words" is uncommon in linguistics for describing linguistic phenomena or classes of words, but is current in logic and philosophy where it was introduced by Kurt Grelling and Leonard Nelson for describing a semantic paradox, later known as Grelling's paradox or the Grelling-Nelson paradox.[1]
The fame of this paradox later extending also to non-academic circles has created a more widespread popular interest, expressing itself in more recent times also in the creation of lists of autological words.[2]
One source of autological words are archetypal words (ostensive definition) – words chosen to describe a phenomenon by using an example of the phenomenon, which are thus necessarily autological. One such example is a mondegreen – a mishearing of a phrase, which itself is based on a mishearing of "And laid him on the green" as "And Lady Mondegreen".
We can ask if autological is itself an autological word? This leads to an infinite regress: autological is autological if it expresses the property of expressing the property which it also expresses. An even more problematic paradox arises when we ask whether the word 'heterological' is itself heterological.