The most common and most likely answer to this crossword clue is the 3 plus 3 plus 1 plus 2 plus 4 letter word LET RIP - LE TRIP
I've seen this crossword clue in The Times
L
E
T
R
I
P
-
L
E
T
R
I
P
Buddy explains!
The straight part
We know that "Talk aggressively" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case talk aggressively = let rip - le trip.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.