The most common and most likely answer to this crossword clue is the 10 letter word LION-TAMER
I've seen this crossword clue in The Guardian
L
I
O
N
-
T
A
M
E
R
More clues leading to the result LION-TAMER
Buddy explains!

The straight part
We know that "One keeps pride in check" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one keeps pride in check = lion-tamer.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.