Impressive ewe Amos butchered (7)
I believe the answer is:
awesome
'impressive' is the definition.
(similar in meaning)
'ewe amos butchered' is the wordplay.
'butchered' indicates anagramming the letters (I've seen this in other clues).
'ewe'+'amos'='eweamos'
'eweamos' with letters rearranged gives 'AWESOME'.
(Other definitions for awesome that I've seen before include "Extraordinary" , "Stupendous" , "wizard" , "staggering" , "Inspiring fear and wonder" .)