Boat smashed around river: scrap mission? (5)
I believe the answer is:
abort
'scrap mission?' is the definition.
'abort' can be an answer for 'scrap' (I've seen this in another clue). I am not certain of the 'mission?' bit.
'boat smashed around river' is the wordplay.
'smashed' indicates anagramming the letters.
'around' means one lot of letters goes inside another.
'river' becomes 'r' (abbreviation for river).
'boat' anagrammed gives 'abot'.
'abot' enclosing 'r' is 'ABORT'.
Can you help me to learn more?
(Other definitions for abort that I've seen before include "Bring further progress to an end" , "Stop prematurely" , "Miscarry" , "Cut short" , "Bring to a premature end" .)