"extent," 1530s, "room to act," from Italian scopo "aim, purpose, object, thing aimed at, mark, target," from Latin scopus, from Greek skopos "aim, target, object of attention; watcher, one who watches" from metathesized form of PIE *spek-yo-, suffixed form of root *spek- "to observe." Sense of "distance the mind can reach, extent of view" first recorded c. 1600.