The most common and most likely answer to this crossword clue is the 8 letter word FALSTAFF
I've seen this crossword clue in Financial Times
F
A
L
S
T
A
F
F
More clues leading to the result FALSTAFF
- Opera produced by crew on river
- Fat knight’s first to swim in a couple of rivers
- Shakespearean character‘s strong metal rod
- Timeless, fat, ultimately fictional man!
- Man on river, a Boar’s Head regular
- Sir John‘s employees on the river
- Dissolute character with people at work by river
- Roguish character, ultimate in thorns between two flowers
- Opera, Parsifal, staffer includes
- Disreputable knight‘s man on river …
Buddy explains!
The straight part
We know that "Roguish character" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case roguish character = falstaff.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.