It can fix things with safety (3)
I believe the answer is:
pin
This clue might be a double definition.
'it can fix things' is the first definition.
The definition suggests a singular noun which matches the answer.
'safety' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'with' acts as a link.
Can you help me to learn more?
(Other definitions for pin that I've seen before include "Flagged stick placed in golf hole" , "Badge" , "Hold (down)" , "Skittle; chess attack" , "Small pointed metal fastener" .)