The most common and most likely answer to this crossword clue is the 10 letter word MOTHBALLED
I've seen this crossword clue in The Guardian
M
O
T
H
B
A
L
L
E
D
Buddy explains!
The straight part
We know that "put on hold" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case put on hold = mothballed.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 MOTHBALLED mean?
MOTHBALLED verb- To store or shelve something no longer used.
- To stop using (something), but keep it in good condition.
- (of something out of use) Kept in good condition for possible future use.