eroded

Concise Oxford English Dictionary © 2008 Oxford University Press:
erode /ɪˈrəʊd/

▶verb

• 1 (with reference to the action of wind, water, etc. on the land) gradually wear or be worn away.

• 2 gradually destroy or weaken: parliament's authority has been eroded by successive governments.

  ■ Medicine (of a disease) gradually destroy (bodily tissue).

– derivatives
erodible adjective.

– origin C17: from Fr. éroder or L. erodere, from e- (var. of ex-) ‘out, away’ + rodere ‘gnaw’.