Position east of Charlie on European lake (9)
I believe the answer is:
constance
'european lake' is the definition.
(Lake Constance in central Europe)
'position east of charlie on' is the wordplay.
'position' becomes 'stance' (stance is a kind of position).
'east of' means one lot of letters go next to another (some letters go to the right of others).
'charlie' becomes 'C' (phonetic alphabet: alpha, bravo, charlie etc.).
'c'+'on'='con'
'stance' put after 'con' is 'CONSTANCE'.
(Other definitions for constance that I've seen before include "Lady Chatterley, for example" , "Lady Chatterley, say" , "that's held by various national banks" , "Spry flower arranger" , "she has taken" .)