Alpha male held in very serious respect (6)
I believe the answer is:
admire
'respect' is the definition.
(admiring is a kind of respecting)
'alpha male held in very serious' is the wordplay.
'alpha' becomes 'a' (phonetic alphabet: alpha, bravo, charlie etc.).
'male' becomes 'm' (common abbreviation).
'held in' means one lot of letters goes inside another.
'very serious' becomes 'dire' (I can't justify this - if you can you should believe this answer much more).
'm' put into 'dire' is 'dmire'.
'a'+'dmire'='ADMIRE'
Can you help me to learn more?
(Other definitions for admire that I've seen before include "Look at (someone or something) with pleasure" , "Revere" , "Regard approvingly" , "'Esteem, appreciate (6)'" , "Have respect for, esteem" .)