Bill has coin with special significance (6)
I believe the answer is:
accent
'special significance' is the definition.
'accent' can be an answer for 'significance' (thesaurus). I'm unsure of the 'special' bit.
'bill has coin' is the wordplay.
'bill' becomes 'ac' (short for account).
'has' means one lot of letters go next to another.
'coin' becomes 'cent' (cent is a kind of coin).
'ac'+'cent'='ACCENT'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for accent that I've seen before include "it could be grave" , "Stress, emphasis" , "Distinctive way of pronouncing language" , "Underline" , "Distinctive way of talking" .)