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

• molecules
• mole drain
• mole drainer
• mole drainers
• mole-electronics
• mole-eyed
• molehill
• molehills
• mole hunt
• mole hunter
• mole hunters
• mole hunts
• palaeographist
• palaeographists
• palaeography
• palaeoichthyologic
• palaeoichthyological
• palaeoichthyologist
• palaeoichthyologists
• palaeoichthyology
• Palaeo-Indian
• palaeolimnological
• palaeolimnologist
• palaeolimnologists
• palaeolimnology