Line in amusing taunt that can be swapped (8)

I believe the answer is:

fungible

'that can be swapped' is the definition.

'line in amusing taunt' is the wordplay.
'line' becomes 'l'.
'in' means one lot of letters goes inside another.
'amusing' becomes 'fun' ('fun' can be a synonym of 'amusing').
'taunt' becomes 'gibe' (gibing is a kind of taunting).
'fun'+'gibe'='fungibe'
'l' placed within 'fungibe' is 'FUNGIBLE'.

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app