Definition of substage in English:

substage

noun

usually as modifier
  • An apparatus fixed beneath the ordinary stage of a compound microscope to support mirrors and other accessories.

    ‘Even though the digital images are generally good, important details of the tissues are often lost that might be enhanced with appropriate adjustments of a real microscope (focus and substage diaphragm adjustments).’
    ‘For microscopic examination of the vaginal discharge, warming the slide and decreasing the intensity of substage lighting are ways to increase sensitivity for trichomonads.’

Pronunciation

substage

/ˈsʌbstɛɪdʒ/