Support without backup (5)
I believe the answer is:
stool
'support' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stool that I've seen before include "Armless seat" , "place butt on one?" , "Backless chair" , "Three-legged backless seat" , "item of furniture here" .)