Aircraft reviewing ridge around lake (6)
I believe the answer is:
glider
'aircraft' is the definition.
(glider is a kind of aircraft)
'reviewing ridge around lake' is the wordplay.
'reviewing' indicates anagramming the letters (To re view).
'around' is an insertion indicator.
'lake' becomes 'L' (geographical abbreviation).
'ridge' anagrammed gives 'gider'.
'gider' placed around 'l' is 'GLIDER'.
(Other definitions for glider that I've seen before include "Powerless aircraft" , "Aircraft supported solely by air" , "Girdle for silent flier" , "Engineless plane" , "quiet flier" .)