limn: Think of 'Film' i.e. Picture, Drawing.
limn--lime..imagine u r tracing the shape of or drawing the picture of lime tree.
limn ... m out --- lin (e)
Remember in hindi we had Nimnalikhit
LIMN=ILLUMINATE. The root of LIMN is "luminare"=illuminate. LIMN means to illuminate through illustration.
LIMN means to delineate or outline. To remember, spell both words like this: deLIMNeate and outLIMN.