Awful deed, act I commit (8)
I believe the answer is:
dedicate
'commit' is the definition.
(I know that commit can be written as dedicate)
'awful deed act i' is the wordplay.
'awful' is an anagram indicator.
'deed'+'act'+'i'='deedacti'
'deedacti' with letters rearranged gives 'DEDICATE'.
(Other definitions for dedicate that I've seen before include "Devote to a special purpose, say time or energy" , "Address (eg, a book to a person)" , "Commit" , "Devote (to), pledge (to)" , "Devote, address, to" .)