Is it just too too short for off-stage wear? (4)
I believe the answer is:
tutu
'wear?' is the definition.
(tutu is a kind of wear)
'is it just too too short for off-stage' is the wordplay.
'is it' becomes 't' (abbreviation. e.g. in 'tis).
'just too too short for off-stage' becomes 'utu' (I can't justify this - if you can you should believe this answer much more).
't'+'utu'='TUTU'
Can you help me to learn more?
(Other definitions for tutu that I've seen before include "South African archbishop, b. 1931" , "Ballet dancer's costume" , "8 [BALLET] term" , "very short garment" , "The old primate" .)