upsilon /ūp-sīˈlon, ŭp-, ūpˈsi- or upˈsi-/ or ypsilon /ip-sīˈlon or ipˈsi-/

1. The twentieth letter of the Greek alphabet (Υ, υ)
2. As a numeral υˈ = 400, ˌυ = 400000
3. A short-lived heavy subatomic particle produced when beryllium nuclei are bombarded with high-energy protons

• adolescence
• adolescences
• adolescent
• adolescents
• Adonai
• Adonia
• Adonic
• Adonis
• adonise
• adonised
• adonises
• adonising
• adonize
• adonized
• adonizes
• adonizing
• adoors
• adopt
• adopted
• adoptee
• adoptees
• adopter
• adopters
• Adoptianism
• adoptianist