The most common and most likely answer to this crossword clue is the 7 letter word EX-WIFE
I've seen this crossword clue in The Times
E
X
-
W
I
F
E
Buddy explains!
The straight part
We know that "Old Dutch" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old dutch = ex-wife.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 EX-WIFE mean?
EX-WIFE noun- A former wife