Definition of substitution. 1  1a : the act, process, or result of substituting one thing for anotherb : replacement of one mathematical entity by another of equal value. 2  2 : one that is substituted for another.
Homogenized milk is any sort of milk that has been mechanically treated to ensure that it has a smooth, even consistency. The homogenization process typically involves high temperatures, agitation, and filtration, all aimed at breaking down milk's naturally occurring fat molecules.
Organic milk. A glass of milk. Organic milk refers to a number of milk products from livestock raised according to organic farming methods. In most jurisdictions, use of the term organic or equivalents like bio or eco, on any product is regulated by food authorities.