The most common and most likely answer to this crossword clue is the 6 letter word POMMEL
I've seen this crossword clue in Financial Times
P
O
M
M
E
L
Buddy explains!

The straight part
We know that "hit repeatedly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hit repeatedly = pommel.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 POMMEL mean?
POMMEL noun- The upper front brow of a saddle.
- A rounded knob or handle.
- The bat used in the game of knurr and spell or trap ball.
- To pound or beat.