Travellers in train set out (10)
I believe the answer is:
itinerants
'travellers' is the definition.
(itinerant is a kind of traveller)
'in train set out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'in'+'train'+'set'='intrainset'
'intrainset' is an anagram of 'ITINERANTS'.
(Other definitions for itinerants that I've seen before include "Point and talk wildly in view of island" , "Travellers" .)