Camelot knight hoisted silver flag in the air (6)
I believe the answer is:
gawain
'camelot knight' is the definition.
'gawain' can be an answer for 'knight' (Sir Gawain is a knight in Arthurian legend). I'm unsure of the 'camelot' bit.
'hoisted silver flag in the air' is the wordplay.
I cannot really understand how this works, but
'in' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gawain that I've seen before include "round a table for him and his comrades?" , "Man at round table" , "K" , "One of King Arthur's knights" , "Arthurian knight of the Round Table" .)