The most common and most likely answer to this crossword clue is the 7 letter word ASUNDER
I've seen this crossword clue in The Daily Telegraph
A
S
U
N
D
E
R
More clues leading to the result ASUNDER
- Apart, ut infra
- In pieces and sure to be put together somehow
- In pieces, in the manner indicated below
- “Up”, like “down”?
- A German article about star is in at least two parts
- Apart from some enigmas, understood
- A local star embarrassed about being in two pieces
- Into pieces like a French and German article
- Apart and sure to be different
- Paper splits English and German articles into pieces
Buddy explains!

The straight part
We know that "separately" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case separately = asunder.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 ASUNDER mean?
ASUNDER adverb- Into separate parts or pieces.