Rod left in a split second, maybe (7)
I believe the answer is:
ordinal
'second maybe' is the definition.
('second' is the ordinal for the number two)
'rod left in a split' is the wordplay.
I cannot really see how this works, but
an anagram of 'rod' is 'ord' which is within the answer.
'left' could be 'al' (I've seen this in other clues) and 'al' is found in the answer.
'in' is within the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
(Other definitions for ordinal that I've seen before include "First, second, third etc." , "Maybe first" , "Of position in series; service book (hist.)" , "The associate of Cardinal" , "E.g. first" .)