The most common and most likely answer to this crossword clue is the 8 letter word SPILLAGE
I've seen this crossword clue in The Times
S
P
I
L
L
A
G
E
More clues leading to the result SPILLAGE
- What's lost by guru bottling medicine?
- What's fallen out of second sack
- Overflow from small sack
- Small sack of waste
- Man wise to accept medication for drinking problem
- End of copious loot? There’s evidence of waste
- Wise man taking medicine for problem with waterworks?
- Waste small space for writing, wrongly filled
- Wise to restrict pressure before bad overflow
- Liquid lost through skinhead’s aggressive behaviour
Buddy explains!

The straight part
We know that "Overflow" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case overflow = spillage.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SPILLAGE mean?
SPILLAGE noun- The process or action of spilling.
- That which has been spilled.