The most common and most likely answer to this crossword clue is the 10 letter word EMIGRATION
I've seen this crossword clue in The Daily Telegraph
E
M
I
G
R
A
T
I
O
N
Buddy explains!

The straight part
We know that "going abroad" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case going abroad = emigration.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 EMIGRATION mean?
EMIGRATION noun- The act of emigrating; movement of a person or persons out of a country or national region, for the purpose of permanent relocation of residence.
- A body of emigrants; emigrants collectively