It may be paid in, including silver (6)
I believe the answer is:
homage
'it may be paid' is the definition.
(as in 'to pay homage')
'in including silver' is the wordplay.
'in' becomes 'home' ('he's in' can mean 'he's home').
'including' means one lot of letters goes inside another.
'silver' becomes 'ag' (Ag is the chemical symbol for silver).
'home' enclosing 'ag' is 'HOMAGE'.
(Other definitions for homage that I've seen before include "Due respect" , "Things said as mark of respect" , "Formal expression of respect" , "Public honour and respect" , "Public show of respect" .)