“The term parameter, which originates in mathematics, has a number of specific meanings in fields such as astronomy, electricity, crystallography, and statistics.”

Perhaps because of its ring of ‘technical authority’, it has been used more generally in recent years to refer to any factor that determines a range of variations and especially to a factor that restricts what can result from a process or policy. In this use it often comes close to meaning ”a limit or boundary.” Some of these new uses have a clear connection to the technical senses of the word. For example, the provisions of a zoning ordinance that limit the height or density of new construction can be reasonably likened to mathematical parameters that establish the limits of other variables. Therefore one can say : ”The zoning commission announced new planning parameters for the historic district of the city”. But other uses go one step further and treat parameter as a high-toned synonym for ‘characteristic’. There are several difficulties with the nontechnical use of the word ‘parameter’ that may arise from its resemblance to the word ‘perimeter’, with which it shares the sense “limit,” though the precise meanings of the two words differ markedly. This confusion probably explains the use of ‘parameter’ in a sentence such as “U.S. forces report that the parameters of the mine area in the Gulf are fairly well established”, where the word ‘perimeter’ would have expressed the intended sense more exactly.

Other, rarer, confusion occurs when the old English spelling of ‘parametre’ –originating from the French word ‘paramètre’– is employed instead of the now utilized spelling of ‘parameter’ by non-native English speakers using out-of-date English dictionaries.

In general use, ‘parameter’ “refers to a distinguishing characteristic or factor, especially one that can be measured or quantified: the parameters of light are brightness and colour. It has come to be used loosely to mean a limit. This is not incorrect, but it sounds like jargon. Before using it consider whether limit; scope; boundary, or a similar word would be more suitable.” (excerpt from the online Dictionary of English)