The most common and most likely answer to this crossword clue is the 8 letter word BESTRIDE
I've seen this crossword clue in The Guardian
B
E
S
T
R
I
D
E
More clues leading to the result BESTRIDE
- Stand across from top amusement park attraction
- Most excellent journey on horseback, with one leg on either side
- Mount the favourite?
- Dominate worst tour
- Get on website regularly blocking “The Woman in White”
- Have a leg either side of top fairground attraction
- Set out, partner’s admitted, to get leg over
- Mount finest horse
- Sit a certain way for the ideal journey?
- Dominate finest horse
Buddy explains!

The straight part
We know that "Dominate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dominate = bestride.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 BESTRIDE mean?
BESTRIDE verb- To be astride something, to stand over or sit on with legs on either side, especially to sit on a horse.
- To stride over, or across.
- To dominate.