The most common and most likely answer to this crossword clue is the 7 letter word PRIMACY
I've seen this crossword clue in The Sunday Telegraph
P
R
I
M
A
C
Y
Buddy explains!
The straight part
We know that "Dominance shown" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dominance shown = primacy.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PRIMACY mean?
PRIMACY noun- The state or condition of being prime or first, as in time, place, rank, etc.
- Excellence; supremacy.
- The office, rank, or character of a primate, it being the chief ecclesiastical station or dignity in a national church
- The office or dignity of an archbishop