- Any substance applied to wood that helps it resist decay, rotting, or harmful insects.
- Any substance added to food capable of inhibiting, retarding or arresting the growth of microorganisms or of any deterioration of food caused by microorganisms or capable of masking the evidence of any such deterioration. Traditional preservatives included salt, sugar, saltpetre, acids or alcohol. Numbers of synthetic substances and derivatives of natural substances are also used. These are identified by E numbers between 200 and 299.
- noun a substance, e.g. sugar or salt, added to food to preserve it by slowing natural decay caused by bacteria