zero (n.) Look up zero at Dictionary.com
"figure which stands for naught in the Arabic notation," also "the absence of all quantity considered as quantity," c.1600, from French zéro or directly from Italian zero, from Medieval Latin zephirum, from Arabic sifr "cipher," translation of Sanskrit sunya-m "empty place, desert, naught" (see cipher (n.)).

A brief history of the invention of "zero" can be found here. Meaning "worthless person" is recorded from 1813. As an adjective from 1810. Zero tolerance first recorded 1972, originally U.S. political language. Zero-sum in game theory is from 1944 (von Neumann), indicating that if one player wins X amount the other or others must lose X amount.
zero (v.) Look up zero at Dictionary.com
in zero in, 1944, from zero (n.); the image is from instrument adjustment to a setting of "zero" (1909 in this sense, originally in rifle-shooting). Related: Zeroed; zeroing.