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

• full dress
• full-dress
• full-dress debate
• full-dress debates
• fulled
• fuller
• fullerene
• fullerenes
• fullers
• fuller's earth
• fuller's-herb
• fullest
• full-eyed
• full-face
• full-faced
• full-fashioned
• full-fed
• full-fledged
• full fling
• full-fraught
• full-front
• full-frontal
• full-frontals
• full-grown
• full hand