Strained muscle, ultimately, that stops tennis shot (7)
I believe the answer is:
intense
'strained' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'muscle ultimately that stops tennis shot' is the wordplay.
'ultimately' indicates one should take the final letters.
'that stops' indicates putting letters inside.
'shot' is an anagram indicator.
The last letter of 'muscle' is 'e'.
'tennis' with letters rearranged gives 'intnse'.
'e' placed inside 'intnse' is 'INTENSE'.
Can you help me to learn more?
(Other definitions for intense that I've seen before include "Acute difficulty" , "Of extreme force" , "Acute, vivid" , "Forceful, concentrated" , "Strong in quality or degree - perhaps a feeling" .)