word-forming element meaning "outside; beyond the scope of; in addition to what is usual or expected," in classical Latin recorded only in extraordinarius, but more used in Medieval Latin and modern formations; it represents Latin extra (adv.) "on the outside, without, except," the old fem. ablative singular of exterus "outward, outside," comparative of ex "out of" (see ex-).
1798, "pertaining to driving or carriages;" from Latin curriculum "fast chariot" (from currere "to run, move quickly;" from PIE root *kers- "to run") + -ar. From 1881 in reference to systems of education.