Order is about right support for climbers (7)
I believe the answer is:
trellis
'support for climbers' is the definition.
(I've seen this before)
'order is about right' is the wordplay.
'order' becomes 'tell' ('tell' can be a synonym of 'order'**).
'about' means one lot of letters goes inside another.
'right' becomes 'r' (common abbreviation).
'tell'+'is'='tellis'
'tellis' enclosing 'r' is 'TRELLIS'.
(Other definitions for trellis that I've seen before include "Rose clambers over this" , "Garden frame or screen" , "Light framework for climbing plants" , "Framework - stiller (anag)" , "Structure supporting climbing plants" .)