Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sŭb-ĕdo, ēdi, 3, v. a., to eat, waste, or wear away below: e scopulo, quem rauca subederat unda, Ov. M. 11, 783; Hier. in Jer. 1, 2, 37.