n.
Function: adjective
Date: 1810
1 a : of, relating to, or being a zero b : having no magnitude or quantity : not any < zero growth> < zero tolerance> c (1) : having no phonetic manifestation <the zero modification in the past tense of cut > (2) : having no modified inflectional form <a zero plural>
2 a of a cloud ceiling : limiting vision to 50 feet (15 meters) or less b of horizontal visibility : limited to 165 feet (50.3 meters) or less