What is the meaning of Once?

One and only one time.

Formerly; during some period in the past.

At any time; ever.

One day, someday.

Multiplied by one: indicating that a number is multiplied by one.

As soon as; when; after.

Obsolete form of ounce.

eleven

eleven

ounce (avoirdupois ounce)

a little bit

snow leopard

ounce

eleven

plural of oncia

alternative form of ones

eleven

elevenses, snack (bread with tea or coffee)

Source: wiktionary.org