The most common and most likely answer to this crossword clue is the 8 letter word RABBITED
R
A
B
B
I
T
E
D
Buddy explains!

The straight part
We know that "Went on" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case went on = rabbited.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 RABBITED mean?
RABBITED verb- To hunt rabbits.
- To flee.
- To talk incessantly and in a childish manner; to babble annoyingly.