What does the cryptic crossword clue "Karen joining odyssey travelling for a long time (7,5)" mean?

The wordplay uses an anagram. anagram of KAREN + ODYSSEY = DONKEYSYEARS The answer is DONKEYSYEARS.

Karen joining odyssey travelling for a long time (7,5)

Guardian Cryptic #28974 | 10 Down | 2023-01-23 flower