Mastery (7)
'mastery' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dominance that I've seen before include "Mastery" , "Influence (over others)" , "Power (over others)" , "Ascendancy" , "top position" .)
'mastery' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for prowess that I've seen before include "Great ability or daring" , "Superior skill or ability" , "Mastery - talent" , "Outstanding skill" , "Skill, expertise; bravery" .)