The article deals with the verbs formed with the unproductive marker -ra / -rye in Tundra Nenets. Such verbs are intransitive, perfective, and are inflected, as a rule, in the forms of the reflexive conjugation. Morphosyntactically, the function of this marker in combination with transitive verbs can be considered passive. The addition of the marker is also possible for some intransitive verbs and nominal stems. Denominal verbs show a double manifestation of “passive” morphology and allow to promote into the subject position a participant that is absent in the argument structure. Semantically, the majority of passive derivatives are united by their use mainly in adversative contexts. The emergence of adversative usage may be related to the presence of causative-passive syncretism and P-lability.