The most common and most likely answer to this crossword clue is the 5 letter word LUMPS
L
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More clues leading to the result LUMPS
Buddy explains!

The straight part
We know that "Aggregates" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case aggregates = lumps.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 LUMPS mean?
LUMPS noun- Something that protrudes, sticks out, or sticks together; a cluster or blob; a mound or mass of no particular shape.
- A group, set, or unit.
- A small, shaped mass of sugar, typically about a teaspoonful.
- A dull or lazy person.
- (as plural) A beating or verbal abuse.
- A projection beneath the breech end of a gun barrel.
- A kind of fish, the lumpsucker.
- Food given to a tramp to be eaten on the road.
- A beating or verbal abuse.