It can be worn back to front (3)
I believe the answer is:
bib
'it can' is the definition.
The definition suggests a singular noun which matches the answer.
'worn back to front' is the wordplay.
'worn' becomes 'bi' (I am not sure about this - if you are sure you should believe this answer much more).
'to front' suggests taking the first letters.
The first letter of 'back' is 'b'.
'bi'+'b'='BIB'
'be' is the link.
Can you help me to learn more?
(Other definitions for bib that I've seen before include "-- and tucker" , "Baby's feeding cloth" , "Tempest airy spirit" , "Protective apron" , "Baby-feeding cloth" .)