Combined effect of two or more factors which is smaller than the solitary effect of any one of those factors. Note: In bioassays, the term may be used when a specified effect is produced by exposure t [..]

Term used to refer to what happens when chemical is exposed to another chemical.

1797, from French antagonisme or directly from late Greek antagonisma, noun of action from antagonizesthai "to struggle against" (see antagonist).

The joint effect of two or more drugs such that the combined effect is less than the sum of the effects produced by each agent separately. The agonist is the agent producing the effect that is diminis [..]

The effect of a deficiency or toxicity of an element that restricts or interferes with the uptake.

hostility: a state of deep-seated ill-will the relation between opposing principles or forces or factors; "the inherent antagonism of capitalism and socialism" an actively ex [..]

n. Mutual opposition or resistance of counteracting forces, principles, or persons.

The condition of being an opposing principle, force, or factor, as when two hormones have opposite effects on target tissues. antagonist

  An interaction between two organisms (e.g., moulds or bacteria) in which the growth of one is inhibited by the other. cf 

The mutual killing, injury or inhibition of growth of dissimilar organisms occupying the same ecological niche.

(n) a state of deep-seated ill-will(n) the relation between opposing principles or forces or factors(n) an actively expressed feeling of dislike and hostility(n) (biochemistry) interference in or inhi [..]

Interference or inhibition of the effect of one chemical by the action of another.

Interference or inhibition of the effect of one chemical by the action of another.

Phenomena and pharmaceutics of compounds that inhibit the function of agonists (Drug Agonism) and inverse agonists (Drug Inverse Agonism) for a specific receptor. On their own, antagonists produce no [..]

A natural Association between organisms that is detrimental to at least one of them. This often refers to the production of chemicals by one microorganism that is harmful to another.

a relationship between different organisms in which one partly or completely inhibits the growth of another or kills it. The term is usually applied to the effects of toxic metabolites of one organism [..]

An interaction between chemicals in which one partially or completelyinhibits the effect of the other (for example, a drug that blocks a hormone's receptor site would be a hormone antagonist). (09 Oct 1997)

The effect of a deficiency or toxicity of an element that restricts or interferes with the uptake.

When the adverse effect or risk from two or more chemicals interacting with each other is less than what it would be if each chemical was acting separately.

Opposiong effects produced by drugs, hormons etcç on living systems.