Coffee encountered, getting knocked over (5)
I believe the answer is:
decaf
'coffee' is the definition.
(I've seen this before)
'encountered getting knocked over' is the wordplay.
'encountered' becomes 'faced' (facing is a kind of encountering).
'getting knocked over' says the letters should be written in reverse.
'faced' backwards is 'DECAF'.
(Other definitions for decaf that I've seen before include "Style of coffee" , "Non-alcoholic drink" , "Cup substitute missing kick" , "Type of coffee" , "Coffee without the kick?" .)