Lake in Germany ridiculed - provided tiny amount of water (8)
I believe the answer is:
dribbled
'provided tiny amount of water' is the definition.
(to dribble is to release a small amount of water)
'lake in germany ridiculed' is the wordplay.
'lake' becomes 'l' (geographical abbreviation).
'in' means one lot of letters goes inside another.
'germany' becomes 'd' (vehicle registration code for Deutschland).
'ridiculed' becomes 'ribbed' ('rib' can be a synonym of 'ridicule').
'd'+'ribbed'='dribbed'
'l' put within 'dribbed' is 'DRIBBLED'.
(Another definition for dribbled that I've seen is " Drooled".)