"to cut off or away," 1610s, from Latin abscisus, past participle of abscidere "to cut away," from ab "off, away from" (see ab-) + caedere "to cut, cut down" (from PIE root *kae-id- "to strike"). Related: Abscised; abscising.
word-forming element meaning "away, from, from off, down," denoting disjunction, separation, departure; from Latin ab (prep.) "off, away from" in reference to space or distance, also of time, from PIE root *apo- "off, away" (also the source of Greek apo "off, away from, from," Sanskrit apa "away from," Gothic af, English of, off; see apo-).
The Latin word also denoted "agency by; source, origin; relation to, in consequence of." Since classical times usually reduced to a- before -m-, -p-, or -v-; typically abs- before -c-, -q-, or -t-.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit skhidati "beats, tears;" Latin caedere "to strike down, fell, slay;" Lithuanian kaišti "shave;" Armenian xait'em "to stab;" Albanian qeth "to shave;" Middle Dutch heien "to drive piles," Old High German heia "wooden hammer," German heien "beat."
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Harper, D. (n.d.). Etymology of abscise. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/abscise