Spilled out having taken too much in capturing squat (10)
I believe the answer is:
overflowed
'spilled' is the definition.
(overflowing is a kind of spilling)
'having taken too much in capturing squat' is the wordplay.
I cannot really understand how this works, but
'squat' could be 'low' (similar in meaning) and 'low' is found within the answer.
'taken' could be 'fed' (feeding is a kind of taking) and 'fed' is present in the remaining letters.
'too much' could be 'over' (over can mean to too great an extent) and 'over' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'out' is the link.
Can you help me to learn more?
(Another definition for overflowed that I've seen is " Ran out of too full vessel".)