Rugby player tucked in, devouring a good spread (9)
I believe the answer is:
propagate
'spread' is the definition.
(I know that spread can be written as propagate)
'rugby player tucked in' is the wordplay.
'rugby player' becomes 'prop' (position in rugby).
'tucked in' becomes 'agate' (I am not sure about this - if you are sure you should believe this answer much more).
'prop'+'agate'='PROPAGATE'
'devouring a good' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
(Other definitions for propagate that I've seen before include "Multiply, transmit" , "Produce more" , "widely spread" , "Grow (plants) or spread (ideas)" , "Publicise" .)