He may get a line from Hanoi (4)
I believe the answer is:
noah
'line from hanoi' is the definition.
The definition suggests a singular noun which matches the answer.
'he may get a' is the wordplay.
'he may' becomes 'noh' (I can't justify this - if you can you should believe this answer much more).
'get' indicates putting letters inside.
'noh' placed around 'a' is 'NOAH'.
Can you help me to learn more?
(Other definitions for noah that I've seen before include "Animal rescuer" , "The first boatbuilder?" , "Ham's father" , "Ark-builder" , "A host of animals" .)