This dominant male may come first (5)
I believe the answer is:
alpha
This clue could be a double definition.
'this dominant male may come' is the first definition.
'alpha' can be an answer for 'dominant' (I've seen this before). I'm unsure of the rest of the definition.
'first' is the second definition.
(thesaurus)
Can you help me to learn more?
(Other definitions for alpha that I've seen before include "star of utmost brilliance" , "Dominant" , "A for Aristophanes!" , "First, best quality" , "very good rating" .)