mid-14c., resistence, "moral or political opposition;" late 14c., "military or armed physical opposition by force; difficulty, trouble," from Old French resistance, earlier resistence, and directly from Medieval Latin resistentia, from present-participle stem of Latin resistere "make a stand against, oppose" (see resist).
From 1580s as "power or capacity of resisting." The meaning "organized covert opposition to an occupying or ruling power" [OED] is from 1939. The electromagnetic sense of "non-conductivity" is from 1760. Also used in science and engineering with a sense of "force exerted by a medium to retard motion through it," hence the figurative phrase path of least resistance "easiest method or course" (1825), earlier a term in physical sciences and engineering.