Danes designed small chairs (6)
I believe the answer is:
sedans
'chairs' is the definition.
'danes designed small' is the wordplay.
'designed' indicates anagramming the letters (designed with the letters).
'small' becomes 's' (abbreviation - e.g. clothes size).
'danes' with letters rearranged gives 'sedan'.
'sedan'+'s'='SEDANS'
(Other definitions for sedans that I've seen before include "carried chairs" , "Cars" .)