The most common and most likely answer to this crossword clue is the 4 letter word PUPA
I've seen this crossword clue in Independent
P
U
P
A
More clues leading to the result PUPA
- Parent keeps up an appearance of immaturity
- A young creature growing up?
- Each year involves leading intermediate stage
- Immature creature raised in a year
- Entomological specimen at university in Pennsylvania
- Young dog with a growing insect
- Young setter, perhaps a future monarch?
- Immature creature — ant’s first stage as insect
- Not a fully grown creature, whichever way you look at it
- It’s immature and wrong, dad admits
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 PUPA mean?
PUPA noun- An insect in the development stage between larva and adult.