Unusual play with Act I translated (8)
I believe the answer is:
atypical
'unusual' is the definition.
(I know that unusual can be written as atypical)
'play with act i translated' is the wordplay.
'with' is a charade indicator (letters next to each other).
'translated' is an anagram indicator.
'act'+'i'='acti'
'play' put after 'acti' is 'actiplay'.
'actiplay' is an anagram of 'ATYPICAL'.
(Other definitions for atypical that I've seen before include "Not normal" , "'Abnormal, aberrant (8)'" , "exceptional" , "Not characteristic" , "Deviating from what is usual or common" .)