Definition of portentive in English:

portentive

Pronunciation /pɔːˈtɛntɪv/

adjective

rare
  • Having the quality or nature of a portent; ominous, prophetic.

Origin

Late 16th century; earliest use found in Thomas Nashe (d. c1601), writer. From classical Latin portent-, past participial stem of portendere portend + -ive.