zero
n. C / Un. the number 0, which means nothing or none. You use it when there is no amount of something left.
n. the numerical symbol 0 or the absence of any quantity. Often used to indicate the starting point on a scale or a state of total lack.
The temperature dropped to zero last night.
After paying all the bills this month, the balance in my savings account is exactly zero.
In mathematical theory, zero serves as both a placeholder in positional notation and a unique number that represents the additive identity element.
Collectively borrowed from Early Modern Spanish zero, Middle French zero, and (their etymon) Old Italian zero, from Medieval Latin zēphirum, from Arabic صِفْر (ṣifr, “nothing; cipher”), itself calqued from Sanskrit शून्य (śūnyá, “void; nothingness”). Doublet of cipher and chiffre. Cognate with Spanish cero and French zéro.
Often functions as a collective noun for 'nothing'; in plural form 'zeros' or 'zeroes', it refers to the physical digits.