The most common and most likely answer to this crossword clue is the 6 letter word FOETAL
I've seen this crossword clue in Independent
F
O
E
T
A
L
More clues leading to the result FOETAL
- Adversary cut story short in early stage of development
- Some diplomats and others like what’s yet to be delivered?
- Start of FedEx round, flipping overdue: like someone awaiting delivery?
- Describing an unborn baby of late development
- Film inside of horse before it’s even born
- Form of embryonic transformation assuming life, basically
Buddy explains!

The straight part
We know that "in early stage of development" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in early stage of development = foetal.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 FOETAL mean?
FOETAL adjective- Pertaining to, or connected with, a fetus.