As they say: "Drawn, I'm drawn by the moon" (4)
I believe the answer is:
tide
'i'm drawn by the moon' is the definition.
(the tide is determined by the moon)
'as they say drawn' is the wordplay.
'as they say' indicates a 'sounds like' (homophone) clue.
'drawn' becomes 'tied' ('tie' can be a synonym of 'draw').
'tied' is a homophone of 'TIDE'.
(Other definitions for tide that I've seen before include "Movement of seawater" , "Time and it wait for no man" , "Powerful surge" , "Current, ebb" , "Ocean phase" .)