The traditional system of weights and measures in much of the English-speaking world and some other nations, consisting of tons, pounds, ounces, etc.; miles, yards, feet, inches; gallons and pints, with other units, such as furlongs and gills, that became obsolete longer ago. The imperial system was superseded by the simpler and more efficient metric system in most nations several generations ago, and in scientific notation has been superseded by Système International (SI) units of measurement. (See Appendix for conversion tables.)
Subjects: Public Health and Epidemiology.