Autological

Autological is an adjective used in linguistics and philosophy to describe a word whose meaning applies to itself. In other words, an autological word is one that describes its own property. For example, "polysyllabic" is considered autological because the word itself has multiple syllables; "sesquipedalian" (long words) is autological because the word is itself long. The term is formed from the Greek roots auto- "self" and -logical, and was coined in discussions of self-reference.

Autology contrasts with heterology, the property of words that do not describe themselves. A famous issue is the Grelling–Nelson paradox, proposed by Ludwig Grelling and Leonard Nelson in 1908, which asks whether the word "heterological" is heterological. If it is heterological, it does not describe itself, contradicting its being heterological; if it is not heterological, it describes itself, contradicting its classification.

In modern usage, the autological/heterological distinction is primarily of interest in philosophy of language and semantics as a simple illustration of self-reference, lexical properties, and the limits of self-description. Some words with conventional properties are widely cited as autological, while others are disputed. The concept remains a classic example of paradox arising from self-referential language.