Camp bed next to lake (7)
I believe the answer is:
coterie
'camp' is the definition.
('coterie' can be a synonym of 'camp')
'bed next to lake' is the wordplay.
'bed' becomes 'cot' (cot is a kind of bed).
'next to' says to put letters next to each other.
'lake' becomes 'erie' (Lake Erie is one of the Canadian/US 'Great Lakes').
'cot'+'erie'='COTERIE'
(Other definitions for coterie that I've seen before include "Literary circle" , "Small exclusive circle with a common purpose" , "Exclusive circle of people, clique" , "Set" , "Exclusive social circle" .)