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

• high-rollers
• high-rolling
• highs
• high school
• high schools
• high seas
• high season
• high-seasoned
• high seasons
• high-set
• high sheriff
• high shoe
• high shoes
• high-sighted
• high sign
• high signs
• high societies
• high society
• high-souled
• high-sounding
• high spec
• high-speed
• high-speed steel
• high-spirited
• high spirits