Figure nothing's left in hookah (6)
I believe the answer is:
oblong
'figure' is the definition.
(type of geometrical figure)
'nothing's left in hookah' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'left' becomes 'l' (common abbreviation).
'in' means one lot of letters goes inside another.
'hookah' becomes 'bong' (I can't justify this - if you can you should believe this answer much more).
'l' put within 'bong' is 'blong'.
'o'+'blong'='OBLONG'
Can you help me to learn more?
(Other definitions for oblong that I've seen before include "tablet format?" , "Log on B (anag.)" , "Plane figure that deviates from a square by elongation" , "Figure with opposite sides parallel, longer in one direction" , "Strip for planes" .)