Pronunciation: (pur-mis'iv),[key] —adj. 1. habitually or characteristically accepting or tolerant of something, as social behavior or linguistic usage, that others might disapprove or forbid.
2. granting or denoting permission: a permissive nod. 3. optional.
4. Genetics.(of a cell) permitting replication of a strand of DNA that could be lethal, as a viral segment or mutant gene.