Expedition is turning round a long way off (6)
I believe the answer is:
safari
'expedition' is the definition.
(I know that safari is a type of expedition)
'is turning round a long way off' is the wordplay.
'turning' indicates anagramming the letters.
'round' is an insertion indicator.
'a long way off' becomes 'afar' (I've seen this before).
'is' is an anagram of 'si'.
'si' going around 'afar' is 'SAFARI'.
(Other definitions for safari that I've seen before include "African hunting expeiditon" , "A journey to see or hunt wild animals" , "Expedition to observe animals" , "African hunting expedition" , "Hunting trip" .)