Banish Dutch figure of speech that's come up (6)
I believe the answer is:
deport
'banish' is the definition.
(I've seen this before)
'dutch figure of speech that's come up' is the wordplay.
'dutch' becomes 'd' (common abbreviation).
'figure of speech' becomes 'trope' (trope can mean a figure of speech).
'that's come up' says the letters should be written in reverse.
'trope' reversed gives 'eport'.
'd'+'eport'='DEPORT'
(Other definitions for deport that I've seen before include "Send away, being de trop" , "Remove an unwanted person from a country" , "Banish (undesirable alien?)" , "Expel to another country" , "Send home" .)