Artificial language Ibsen developed orally at first (3)
I believe the answer is:
ido
'artificial language' is the definition.
(Ido is an example)
'ibsen developed orally at first' is the wordplay.
'at first' says to take the initial letters.
The first letters of 'ibsen developed orally' is 'IDO'.
(Other definitions for ido that I've seen before include "Artificial language" , "Marriage response" , "Required affirmative in wedding ceremony" , "International language" , "Obscure language" .)