“–verb (used with object)
||to bite or chew on, esp. persistently.
||to wear away or remove by persistent biting or nibbling.
||to form or make by so doing: to gnaw a hole through the wall.
||to waste or wear away; corrode; erode.
||to trouble or torment by constant annoyance, worry, etc.; vex; plague.
–verb (used without object)
||to bite or chew persistently: The spaniel gnawed happily on a bone.
||to cause corrosion: The acid gnaws at the metal.
||to cause an effect resembling corrosion: Her mistake gnawed at her conscience.”