The most common and most likely answer to this crossword clue is the 7 letter word PLAYPEN
I've seen this crossword clue in Independent
P
L
A
Y
P
E
N
More clues leading to the result PLAYPEN
- Show to write? Something kids can’t get out of
- Drama training knight in enclosure
- Pretend to be a writer, young one imprisoned here?
- Drama writer in junior enclosure
- Drama writer’s device to capture the young
- Scheme involves close to twenty exercises in which small children can lark about
- Take on US prison where child may be behind bars
- Feature of nursery suggested by dramatist?
- Unserious writer is barred for children
- Drama with writer in children’s area
Buddy explains!

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 PLAYPEN mean?
PLAYPEN noun- An enclosure for children to play in.