Incredibly small alpha male in charge (6)
I believe the answer is:
atomic
'incredibly small' is the definition.
'atomic' can be an answer for 'small' ('atomic' can be similar in meaning to 'small'). I'm unsure of the 'incredibly' bit.
'alpha male in charge' is the wordplay.
'alpha' becomes 'a' (phonetic alphabet: alpha, bravo, charlie etc.).
'male' becomes 'tom' (I've seen this before**).
'in charge' becomes 'ic'.
'a'+'tom'+'ic'='ATOMIC'
Can you help me to learn more?
(Other definitions for atomic that I've seen before include "Realting to nuclear energy" , "Referring to tiny particles" , "of bombs" , "Very little" , "Relating to the smallest component of an element" .)