Courier included in languid excursions (5)
I believe the answer is:
guide
'courier' is the definition.
(thesaurus)
'included in languid excursions' is the wordplay.
'included in' says the answer is hidden in the clue.
'GUIDE' is hidden within 'languid excursions'.
(Other definitions for guide that I've seen before include "Travel book" , "One who leads" , "Mentor" , "Steer" , "Lead, direct" .)