15th century, in the meaning defined at sense 1a

Middle English differren, differen, borrowed from Middle French & Latin; Middle French differer "to be different," borrowed (with conjugational change) from Latin differre "to carry away in varying directions, spread abroad, postpone, delay, be unlike or distinct," from dif-, assimilated form of dis- dis- + ferre "to carry, convey"

NOTE: The meanings of Latin differre, in particular the sense "to be unlike or distinct," copy those of Greek diaphérein, formed with the cognate verb phérein "to carry." English differ is not distinct etymologically from defer entry 1; the two were originally variants with stress on either the first or last syllable, with the meanings "delay" and "be unlike" eventually being restricted to one of the two variants.