The most common and most likely answer to this crossword clue is the 10 letter word CONTRIBUTE
I've seen this crossword clue in Financial Times
C
O
N
T
R
I
B
U
T
E
More clues leading to the result CONTRIBUTE
Buddy explains!
The straight part
We know that "Be partly responsible for" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case be partly responsible for = contribute.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 CONTRIBUTE mean?
CONTRIBUTE verb- To give something that is or becomes part of a larger whole.