Possibly credit with being straight (6)
I believe the answer is:
direct
'being straight' is the definition.
(similar in meaning)
'possibly credit' is the wordplay.
'possibly' indicates an anagram.
'credit' is an anagram of 'DIRECT'.
'with' acts as a link.
(Other definitions for direct that I've seen before include "Following the quickest and shortest path" , "Straightforward; control" , "Show where to go - straight" , "Immediate - aim" , "Supervise; unambiguous" .)