The past tense of Oversimplify is oversimplified.
verb. ['oʊvɝˈsɪmplɪˌfaɪ'] make too simple.
1. Verb, base form Flowcharts tend to oversimplify these processes in order to make it easier for people to understand.
verb. ['oʊvɝˈsɪmplɪˌfaɪ'] simplify to an excessive degree.