Furious sign (5)
I believe the answer is:
cross
This might be a double definition.
'furious' is the first definition.
(thesaurus)
'sign' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
Can you help me to learn more?
(Other definitions for cross that I've seen before include "Sign - angry" , "anger?" , "Put out" , "Go to the other side" , "Maybe mule" .)