word-forming element meaning "small in size or extent, microscopic; magnifying;" in science indicating a unit one millionth of the unit it is prefixed to; from Latinized form of mikros, Attic form of Greek smikros "small, little, petty, trivial, slight," perhaps from PIE *smika, from root *smik- "small" (source also of Old High German smahi "littleness"), but Beekes thinks it a Pre-Greek word.
1949, "slip of paper, form," especially "the form filled in by foreign guests in French hotels" [OED], from French fiche "card, index card, slip, form" (15c.), verbal noun from Old French fichier "to attach, stick into, pin on" (12c.), from Vulgar Latin *figicare, from Latin figere "to fix, fasten" (from PIE root *dheigw- "to stick, fix"). Sense of "card, strip of film" is a shortening of microfiche (1950).
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dehi- "wall;" Old Persian dida "wall, stronghold, fortress," Persian diz; Latin figere "to fix, fasten, drive, thrust in; pierce through, transfix;" Lithuanian dygstu, dygti "germinate;" Old Irish dingid "presses, thrusts down;" Old English dic "trench, ditch," Dutch dijk "dam."
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<a href="https://www.etymonline.com/word/microfiche">Etymology of microfiche by etymonline</a>
Harper, D. (n.d.). Etymology of microfiche. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/microfiche