The most common and most likely answer to this crossword clue is the 11 letter word APPROXIMATE
I've seen this crossword clue in The Times
A
P
P
R
O
X
I
M
A
T
E
Buddy explains!
The straight part
We know that "loose" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case loose = approximate.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 APPROXIMATE mean?
APPROXIMATE verb- To estimate.
- To come near to; to approach.
- To carry or advance near; to cause to approach.
- Approaching; proximate; nearly resembling.
- Nearing correctness; nearly exact; not perfectly accurate.