New play put on stage, initially for one with big bill (8)
I believe the answer is:
platypus
'one with big bill' is the definition.
(duck-billed platypus)
'new play put on stage initially' is the wordplay.
'new' is an anagram indicator.
'on' says to put letters next to each other.
'initially' suggests taking the first letters.
The first letter of 'stage' is 's'.
'play'+'put'='playput'
'playput' anagrammed gives 'platypu'.
'platypu'+'s'='PLATYPUS'
'for' acts as a link.
(Other definitions for platypus that I've seen before include "Unusual Australian" , "Australian mammal with duckbill" , "Egg-laying mammal" , "Australian egg-layer" , "Australian resident" .)