The most common and most likely answer to this crossword clue is the 10 letter word HOMECOMING
I've seen this crossword clue in The Daily Telegraph
H
O
M
E
C
O
M
I
N
G
More clues leading to the result HOMECOMING
Buddy explains!

The straight part
We know that "return journey" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case return journey = homecoming.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 HOMECOMING mean?
HOMECOMING noun- The act or event of returning home.
- In colleges and high schools, a tradition centred around a football game, a parade and the "coronation" of a Homecoming Queen.