noun
The number zero. Used in counting, mathematics, scores, and temperatures. In everyday contexts, ゼロ is also very common.
気温が零度まで下がった。
The temperature dropped to zero degrees.
彼の得点は零だった。
His score was zero.
ゼロ is the more common everyday word for zero, especially in casual speech and loanword contexts. 零 is more formal or literary, and is the standard kanji representation.
The kanji 零 originally meant 'drizzle' or 'drop' in Chinese, and was later adopted to represent the concept of zero, possibly from the idea of a small, negligible amount. The reading れい is the on'yomi.