As for the etymology the term enemy is derived from Latin language for 'bad friend' (Latin: inimicus). Enemy is a strong word, and emotions associated with the enemy would include anger, hatred, frustration, envy, jealousy, fear, distrust, and possibly grudging respect . As a political concept, an enemy is likely to be met with hate, violence, battle and war. The opposite of an enemy is a friend or ally.
diffusion. 1. The process of rapid random movement of the particles of a liquid or gas which eventually form a uniform mixture. 2. The mixing of substances due to the motion of their particles.
474 pages on this wiki. Diffusion is the net movement of a substance from an area of high concentration to an area of low concentration.This difference in concentration is called the concentration gradient. Concentration gradient-A greater concentration gradient will mean the rate of diffusion increases. 2  This concentration gradient is kept large by removing the substance as it moves across the place where it diffuses.