Transport from A to B (4)
I believe the answer is:
boat
'transport' is the definition.
(boat is a kind of transport)
'from a to b' is the wordplay.
'from' indicates an anagram (from the letters).
'a'+'to'+'b'='atob'
'atob' anagrammed gives 'BOAT'.
(Other definitions for boat that I've seen before include "cat, for example" , "Vessel for travelling on water" , "Water craft" , "Small vessel" , "See 1" .)