Words that define a type of word and also obey that definition [duplicate]

Solution 1:

An autologous word is one that describes itself, such as curt, sesquipedalian, recherché, and septisyllabically.

And autologous. :)

Solution 2:

The OED lists autological with this meaning. Since the first citation (F.P.Ramsey, in 1926) was defining the word (for the purposes of a particular argument), this is a rare case in which one can reasonably say that autological is definitely the correct answer: that is the word which was coined specifically for that meaning.

Autologous is listed in the OED only with a medical meaning, and the first ten pages of results for googling "autologous" contain no non-medical examples.