Finds just the extent of the action taken (8)
I believe the answer is:
measures
'finds' is the definition.
The answer and definition can be both acts as well as being plural nouns.
Maybe they are linked in a way I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for measures that I've seen before include "Determine the dimensions" , "Steps" , "Finds the length of" , "Ascertains the quantity, extent etc." , "Ascertains the size, of dances?" .)