indetectable

in- +‎ detectable

indetectable (comparative more indetectable, superlative most indetectable)

1. Not detectable.
   • 1997 November 7, James Glanz, “ASTROPHYSICS: X-rays Hint at Space Pirouette”, in Science‎, volume 278, number 5340, →DOI, pages 1012–1013:

     Being off kilter is crucial to detecting frame dragging: Within the plane, dragging would produce only indetectable changes in the disk's speed.

   • 1999 October 22, Robert Vassar et al., “{Beta}-Secretase Cleavage of Alzheimer's Amyloid Precursor Protein by the Transmembrane Aspartic Protease BACE”, in Science‎, volume 286, number 5440, →DOI, pages 735–741:

     We first isolated the 12-kD swC99 band, which is nearly indetectable in cells transfected with vector alone (Fig. 5 G).

• undetectable

indetectable m or f (masculine and feminine plural indetectables)

1. undetectable