Definition of black drop in English:

black drop


  • 1Medicine
    historical, rare Medicine. In singular or (rare) plural A dark-coloured liquid medicine composed of opium in vinegar or verjuice with various spices. Now historical.

  • 2Astronomy
    Astronomy. A dark elongation of a planet's disc observed at the start and finish of solar transits of Venus and Mercury when the disc of the planet is just inside and touching the edge of the sun's disc, so that the planet briefly has a pear-shaped appearance elongated towards the sun's edge.


Early 19th century; earliest use found in The Caledonian Mercury. From black + drop.


black drop

/ˌblak ˈdrɒp/