Weird eastern lake (5)
I believe the answer is:
eerie
'weird' is the definition.
(both can mean strange or unsettling)
'eastern lake' is the wordplay.
'eastern' becomes 'e'.
'lake' becomes 'erie' (Lake Erie is one of the Canadian/US 'Great Lakes').
'e'+'erie'='EERIE'
(Other definitions for eerie that I've seen before include "spine-chilling" , "Weird, uncanny" , "Bloodcurdling" , "Mysterious" , "Sinister" .)