The most common and most likely answer to this crossword clue is the 7 letter word ANNEXED
I've seen this crossword clue in The Daily Telegraph
A
N
N
E
X
E
D
Buddy explains!

The straight part
We know that "taken over" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case taken over = annexed.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 ANNEXED mean?
ANNEXED verb- To add something to another thing, especially territory; to incorporate.
- To attach or connect, as a consequence, condition, etc.
- To join; to be united.