Definitions

1. adverb

a Roman numeral denoting the number 70

“The ancient Roman army consisted of around LXX cohorts.”

2. noun

a Roman numeral denoting the number 70

“The LXX was a significant translation of the Hebrew scriptures into Greek.”

3. abbreviation

seventy, as in the LXX Roman numeral

“The LXX represents the number seventy in Roman numerals.”