Arrive, relaxed, around stream (5)
I believe the answer is:
river
'stream' is the definition.
(I know that river is a type of stream)
'arrive relaxed around' is the wordplay.
'around' indicates the answer is hidden within the clue.
'RIVER' is hidden in the letters of 'arrive relaxed'.
(Other definitions for river that I've seen before include "Dee, Exe or Wye, say" , "Eg, Amazon" , "Waterway" , "x or y, so to speak" , "flower" .)