His clothes are clean. (Adjective)
I clean forgot to turn up. (Adverb)
I got clean away. (Adverb)
The adverb CLEAN is used in spoken English mainly with the verb FORGET with the
adverbs AWAY and out and the propositions OVER and THROUGH. The form cleanly is also used as an adjective and an adverb.
The cat is a cleanly animal. (Adjective)
The knife cut cleanly through the bread. (Adverb)