Dada-inspired movement of French - this is just loony at the outset (2,5)
I believe the answer is:
de stijl
'dada-inspired movement of french this is just loony at the outset' is the definition.
The definition suggests a singular noun which matches the answer.
'of french this is just loony at the outset' is the wordplay.
'of french' becomes 'des' (I've seen this in other clues).
'at the outset' suggests taking the first letters (the outset is the beginning).
The initial letters of 'this is just loony' is 'tijl'.
'des'+'tijl'='DE STIJL'
Can you help me to learn more?
(Other definitions for de stijl that I've seen before include "Dutch modern art movement" , "group of Mondrian's" .)