late 14c., "to settle a dispute, determine a controversy," from Old French decider, from Latin decidere "to decide, determine," literally "to cut off," from de "off" (see de-) + caedere "to cut" (from PIE root *kae-id- "to strike"). For Latin vowel change, see acquisition. Sense is of resolving difficulties "at a stroke." Meaning "to make up one's mind" is attested from 1830. Related: Decided; deciding.
*kaə-id-, Proto-Indo-European root meaning "to strike."
It forms all or part of: abscise; avicide; biocide; caesarian; caesura; cement; chisel; -cide; circumcise; circumcision; concise; decide; decision; deicide; excise (v.); excision; felicide; feticide; filicide; floricide; fratricide; fungicide; gallinicide; genocide; germicide; herbicide; homicide; incise; incision; incisor; infanticide; insecticide; legicide; liberticide; libricide; matricide; parricide; patricide; pesticide; precise; precision; prolicide; scissors; senicide; spermicide; suicide; uxoricide; verbicide.
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."
"to have or make scruples, be reluctant to act or decide, have conscientious doubts," 1620s, from scruple (n.). Related: Scrupled; scrupling.