infravisible

English

Etymology

From infra- +‎ visible.

Adjective

infravisible (not comparable)

1. Partially or nearly visible.
   • 1935, American Journal of Syphilis, Gonorrhea and Venereal Diseases:

     The infravisible stage is succeeded by other transition forms before the typical spirochetes develop.

   • 1936, Venereal disease information, page 215:

     These changes with the new formation of □vessels that accompany them seem to favor the development of the infravisible virus into the form of spirochetes.

   • 2013, Rudolphe Durand, The Pirate Organization: Lessons from the Fringes of Capitalism:

     […] the opening up of new spaces is only possible in infravisible limbo or outer space: biopiracy, nanopiracy, and space piracy are arising or will arise.

2. At the infrared end of the spectrum, lower in frequency than light visible to humans.

   Antonym: ultravisible

3. (fantasy) Visible by means of infravision.