Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases. Many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated locally to form a pit or crack, or it can extend across a wide area more or less uniformly corroding the surface.
foe. 1. a person who feels enmity, hatred, or malice toward another; enemy: a bitter foe. 2. a military enemy. 3. an opponent in a game or contest; adversary: a political foe. 4. a person who is opposed in feeling, principle, etc., to something: a foe to progress. 5. a thing that is harmful to or destructive of something.
antagonist. n. 1. an opponent or adversary, as in a contest, drama, sporting event, etc. 2. (Physiology) any muscle that opposes the action of another. Compare agonist 1. 3. (Pharmacology) a drug that counteracts the effects of another drug. Compare synergist 1.strogen antagonist, tamoxifen-an antagonist for estrogen that is used in the treatment of breast cancer. narcotic antagonist-an antagonist used to counteract the effects of narcotics (especially to counteract the depression of respiration).