Scissor is a back-formation from scissors, from Old French cisoires, from Late Latin cisoria, the plural of cisorium ('a cutting instrument'), from caedere ('to cut'); the sc- spelling arose by mistaken association with Latin scindere ('to cut'). The historical chain includes Latin cisorium and Latin caedere. Older glosses in the chain include "a cutting instrument" and "to cut", which help explain the semantic range of the modern word. Morphologically, scissor is best read as back-formation and borrowing, yielding an English verb and noun shaped by both form history and later usage. In current English it functions as a verb and noun, with the sense "to cut with shears; to move with a crossing, snipping action". English derivatives include scissors; related forms include scissors and cisor. The result is an English verb and noun whose etymology preserves the older forms while supporting the word's specialized modern meaning.