1540s, "standing out above a surface," from Latin extantem (nominative extans), present participle of extare "stand out, be visible, exist," from ex- "out" (see ex-) + stare "to stand," from PIE root *sta- "to stand" (see stet). Sense of "in existence" attested in English by 1560s. Related: Extance; extancy, both 17c., both obsolete.