An autonomic word is on one which refers to or describes itself - eg SHORT (short is a short word)

I know a few:

POLYSYLLABIC
ENGLISH
ADJECTIVAL
and my favourite has to be SESQUIPEDALIAN

What others can you think of?
And is AUTONOMIC and autonomic word.......

black, blue, green, red, orange, purple, and yellow

um... does splash count because the sound sounds like the word?

I think that's onomatopoeic (http://en.wikipedia.org/wiki/Onomatopoeia). In that it sounds like the sound it describes. I'm unsure as to whether a word can be both onomatopoeic AND autonomic.