Noun. ( en noun ) Anything that is virtually equal to something else, or has the same value, force, etc. * Macaulay. He owned that, if the Test Act were repealed, the Protestants were entitled to some equivalent . (chemistry) An equivalent weight.
An equivalent (symbol: officially equiv; unofficially but often Eq) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount of another substance in a given chemical reaction. It is an archaic unit of measurement that was used in chemistry and the biological sciences (see Equivalent weight#In history). About for more info here
What is Equivalent?
Stieglitz took at least 220 photographs that he called Equivalent or Equivalents; all feature clouds in the sky. The majority of them show only the sky without any horizon, buildings or other objects in the frame, but a small number do include hills or trees. One series from 1927 prominently features poplar trees in the foreground.