Map makers or graph creators, possibly (13)

I believe the answer is:

cartographers

'map makers' is the definition.
('cartographer' can be a synonym of 'map maker')

'graph creators possibly' is the wordplay.
'possibly' is an anagram indicator.
'graph'+'creators'='graphcreators'
'graphcreators' is an anagram of 'CARTOGRAPHERS'.

'or' acts as a link.

(Another definition for cartographers that I've seen is " Map makers".)

Want a hint initially instead of a full solution? Install my app