prescient

First recorded in 1590–1600; from Old French, from Latin praesciēns (stem praescient- ), present participle of praescīre “to know beforehand,” equivalent to prae- “before” + scīre “to know”; cf. pre-; see science

Prescient “knowing things or events before they exist or happen” comes from Old and Middle French, ultimately from Latin praesciēns (stem praescient- ), the present participle of the verb praescīscere (in Late Latin praescīre ) “to come to know beforehand.”
Going from back to front, praescīscere is a compound verb made up of the inceptive verb scīscere “to get to know” (an inceptive verb is one that shows the beginning of an action), formed from the simple verb scīre “to know” and the inceptive infix -sc-. Prae- is the tricky part: It is the Latin preposition and prefix prae, prae- “in front, ahead, before.”
Even in very early Republican times, Latin country dialects simplified the diphthong ae to ē (or long e ), as in rustic Latin hēdus for urban (that is, Roman) haedus “goat.” By the time of the late Republic, in the first century b.c., and the first century a.d., in early Imperial times, the change from ae to ē became general, first in unaccented vowels and afterward in accented vowels too. By the fourth century, ae and e (or short e ) were also confused, and written texts show baene for Classical Latin bene “well,” and braevis for Classical Latin brevis “short.” The Roman grammarian Servius, in a note on the Aeneid, feels it necessary to explain that miserae is the adjective, not the adverb miserē.
The confusion of ae and e persisted throughout ancient, medieval, and modern times. Even today British English prefers the spelling ae, and Americans the spelling e (especially in scientific and medical terms derived via Latin from Greek), as in anaemia and anemia, haemophilia and hemophilia, leukaemia and leukemia, paediatrics and pediatrics.