Spied moving towards lake, scatter (6)
I believe the answer is:
dispel
'scatter' is the definition.
(synonyms)
'spied moving towards lake' is the wordplay.
'moving' indicates anagramming the letters.
'towards' means one lot of letters go next to another (I've seen this in other clues).
'lake' becomes 'l'.
'spied' with letters rearranged gives 'dispe'.
'dispe'+'l'='DISPEL'
(Other definitions for dispel that I've seen before include "Clear, blow, away" , "Make (feeling) disappear" , "Blow away, scatter" , "Cause to vanish" , "'Disperse, clear away (6)'" .)