Almost perfect goal (4)
I believe the answer is:
idea
'goal' is the definition.
(idea is a kind of goal)
'almost perfect' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'perfect' becomes 'ideal' ('ideal' can be similar in meaning to 'perfect').
'ideal' with its final letter taken away is 'IDEA'.
(Other definitions for idea that I've seen before include "Something imagined in the mind" , "Thought or notion (4)" , "Clue" , "Notion in the mind" , "Plan" .)