Flush, no end, wager disreputable guy is one who travels a lot (12)
I believe the answer is:
globetrotter
'one who travels a lot' is the definition.
(globetrotter can mean someone who travels around)
'flush no end wager disreputable guy' is the wordplay.
'flush' becomes 'glow' (I've seen this in another clue).
'no end' means to remove the last letter.
'wager' becomes 'bet' (synonyms).
'disreputable guy' becomes 'rotter' (rotter can mean a horrible person).
'glow' with its last letter taken away is 'glo'.
'glo'+'bet'+'rotter'='GLOBETROTTER'
'is' acts as a link.
(Other definitions for globetrotter that I've seen before include "Wide-ranging traveller" , "One who travels widely" , "Well-travelled person" , "One travelling widely" , "seasoned traveller" .)