Meaning

• An extract; a preparation, now especially one effective against a certain number of strains of a pathogen.

• The combining capacity of an atom, radical or functional group determined by the number of electrons that it will lose, gain, or share when it combines with other atoms etc.

• The number of binding sites of a molecule, such as an antibody or antigen.

• The number of arguments that a verb can have, including its subject, ranging from zero (for the likes of "It rains") to three (for the likes of "He gives her a flower") or, less commonly, four.

  "The number of bonds that a verb has constitutes what we will call the valence of the verb."

• A one-dimensional value assigned to an object, situation, or state, that can usually be positive or negative.

  "anger and fear have negative valence"

• Value.