Bond one plugging away? On the contrary (6)
I believe the answer is:
adhere
'bond' is the definition.
(synonyms)
'one plugging away? on the contrary' is the wordplay.
I cannot quite see how this works, but
'one' could be 'er' (I've seen this in other clues) and 'er' is found in the answer.
'away?' could be 'a' (abbreviation as used in sports fixtures) and 'a' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for adhere that I've seen before include "Header (anag)" , "Bond" , "Stay attached" , "Stick - join" , "Hold fast, stand by" .)