חַי
chai
Chai means alive, and its two Hebrew letters add up to the number 18
What it means
Chai is the Hebrew word for alive or living. It is written with two letters, chet and yod, and in gematria, the system that gives each Hebrew letter a number, they add up to 18. For that reason 18 has come to stand for life in Jewish culture.
When Israelis say it
Jews customarily give gifts and charity in multiples of 18, such as 36 or 54, which is called giving chai, giving life. The word is also worn as a medallion, like the Star of David and the hamsa. It sits inside the names Chaya for a girl and Chayim for a boy, and inside l'chaim and Am Yisrael chai.
Frequently asked questions
Is Jewish chai the same as chai tea?
No. The tea word comes from Hindustani and Persian words for tea and has nothing to do with the Hebrew chai, which means alive.
Why are gifts given in multiples of 18?
Because chai adds up to 18 in gematria, and 18 is a number of life. Donations of 18, 36 or 54 are a Jewish custom.