All there, some returning from Guatemala to Tonga (5)
I believe the answer is:
total
'all there' is the definition.
(everything)
'some returning from guatemala to tonga' is the wordplay.
'some returning' shows that the letters should be reversed in order.
'from' says the answer is hidden in the clue.
'latot' is hidden in the letters of 'guatemala to tonga'.
'latot' backwards is 'TOTAL'.
(Other definitions for total that I've seen before include "Complete sum" , "Aggregate, sum" , "gross" , "It might be grand" , "Entirety" .)