The most common and most likely answer to this crossword clue is the 8 letter word ODYSSEAN
I've seen this crossword clue in Financial Times
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More clues leading to the result ODYSSEAN
- Essay don constructed about epic poem
- Like a long journey? Yes, and so must get moving
- Like extensive wanderings? Yes, a don’s travels
- One’s days represented as ten years of wandering
- Wandering abroad done, say, when sun is taken in
- Sad? Yes and no, kind of like a crusade
- Long and arduous part of anybody's séance
Buddy explains!

The straight part
We know that "ten years of wandering" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ten years of wandering = odyssean.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.