Totally cool ewe Amos trained (7)
I believe the answer is:
awesome
'totally cool' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'ewe amos trained' is the wordplay.
'trained' is an anagram indicator (to train can mean to grow something into a shape).
'ewe'+'amos'='eweamos'
'eweamos' with letters rearranged gives 'AWESOME'.
Can you help me to learn more?
(Other definitions for awesome that I've seen before include "Magnificent, causing fear or wonder" , "Shocking" , "Inspiring reverential fear" , "Dreadful; amazing" , "Extraordinary" .)