It can carry a humorist ahead (5)
I believe the answer is:
wagon
'it can carry a' is the definition.
The definition suggests a singular noun which matches the answer.
'humorist ahead' is the wordplay.
'humorist' becomes 'wag' (wag is a kind of humorist).
'ahead' becomes 'on' (synonyms).
'wag'+'on'='WAGON'
Can you help me to learn more?
(Other definitions for wagon that I've seen before include "Transport" , "Vehicle (on which abstainers travel?)" , "Vehicle for transporting goods" , "Wheeled vehicle drawn by a horse" , "Four-wheeled goods vehicle" .)