Organised raft tour on medium breeding lake (5,4)
I believe the answer is:
trout farm
'breeding lake' is the definition.
I know nothing about this answer so I can't tell whether this works.
'organised raft tour on medium' is the wordplay.
'organised' indicates an anagram.
'on' says to put letters next to each other.
'medium' becomes 'm' (as in UK clothing sizes).
'raft'+'tour'='rafttour'
'rafttour' is an anagram of 'troutfar'.
'troutfar'+'m'='TROUT-FARM'
Can you help me to learn more?
(Other definitions for trout farm that I've seen before include "place of rainbow?" , "Commercial fish producer" , "river factory" , "Fish-rearing concern" , "Where fish are bred" .)