Angry sign (5)
I believe the answer is:
cross
This clue might be a double definition.
'angry' is the first definition.
(cross can mean annoyed or angry)
'sign' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
Can you help me to learn more?
(Other definitions for cross that I've seen before include "frustrated?" , "SECOND HALF OF 9" , "Stand in the way of" , "something to bear" , "Annoyed - traverse" .)