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late 14c., "measurement, size," from Latin dimensionem (nominative dimensio) "a measuring," noun of action from past participle stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure" (see measure). Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.
dimension di·men·sion (dĭ-měn'shən, dī-)
A measure of spatial extent, especially width, height, or length.
Scope or magnitude.