1. plural of upsilon, the 20th letter of the Greek alphabet (Υ, υ)

Examples

• The physics equation contained several upsilons representing different variables.
• Students learning Greek must memorize the upsilons along with other letters.
• The mathematician wrote multiple upsilons on the blackboard.
• Ancient Greek texts show various forms of upsilons.
• The fraternity’s name included two upsilons in its Greek spelling.