The most common and most likely answer to this crossword clue is the 7 letter word REMARRY
I've seen this crossword clue in The Daily Telegraph
R
E
M
A
R
R
Y
Buddy explains!

The straight part
We know that "Take another partner, for better or worse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case take another partner, for better or worse = remarry.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 REMARRY mean?
REMARRY verb- To marry a second or subsequent time.