What does the cryptic crossword clue "Back in bureau, a seriously hairy man (4)" mean?

The definition is "hairy man". The wordplay uses a hidden word. Hidden reversed in "back in bureaU, A SEriously hairy man" The answer is ESAU.

Back in bureau, a seriously hairy man (4)

Times Cryptic #28653 | 25 Across | 2023-07-12 flower