Desert transport arrived and left (5)
I believe the answer is:
camel
'desert transport' is the definition.
(animal used for transport in a desert)
'arrived and left' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'and' says to put letters next to each other.
'left' becomes 'l' (common abbreviation).
'came'+'l'='CAMEL'
(Other definitions for camel that I've seen before include "Dromedary, perhaps" , "African transport" , "Desert transport" , "Cud-chewing mammal of desert regions" , "African carrier" .)