1 technical a numerical or other measurable factor forming one of a set that defines a system or sets the conditions of its operation:there are three parameters by which a speaker is able to modify the meaning of the utterance—pitch, volume, and tempo
Mathematics a quantity whose value is selected for the particular circumstances and in relation to which other variable quantities may be expressed.
Statistics a numerical characteristic of a population, as distinct from a statistic of a sample.
2a limit or boundary which defines the scope of a particular process or activity:the parameters within which the media work
mid 17th century: modern Latin, from Greek para- 'beside' + metron 'measure'
parameter in other Oxford dictionaries
Definition of parameter in the US English dictionary