Nothing terribly grand that is material (8)
I believe the answer is:
Here is my best explanation:
'material' is the definition.
(organdie is a kind of material)
'nothing terribly grand that is' is the subsidiary indication.
'nothing' becomes 'o' (looks like zero - 0).
'terribly' is an anagram indicator.
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'grand' with letters rearranged gives 'rgand'.
(Other definitions for organdie that I've seen before include "I groaned about translucent fabric", "Orange I'd changed for fine muslin", "Fine stiffened translucent fabric", "I raged on about the fabric", "Oddly ignored a fine cotton muslin", "dress material", "Badly ignored a fine cotton muslin", "Cotton fabric used for dresses", "Cotton muslin" and "Fine material".)