Laugh and rule out taking current transporter (7)
I believe the answer is:
haulier
'transporter' is the definition.
(I have seen 'Commercial transporter ' mean 'haulier' so perhaps 'transporter' could also mean 'haulier')
'laugh and rule out taking current' is the wordplay.
'laugh' becomes 'ha'.
'and' says to put letters next to each other.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'taking' is an insertion indicator.
'current' becomes 'I' (symbol for electric current).
'rule' with letters rearranged gives 'uler'.
'uler' enclosing 'i' is 'ulier'.
'ha'+'ulier'='HAULIER'
(Other definitions for haulier that I've seen before include "Transporter of goods by road" , "Transport contractor" , "Commercial transporter" , "One transports goods in a vehicle" , "Trucker" .)