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

• brenne
• brennes
• brenning
• brens
• Brens
• brent
• brent barnacle
• brenter
• brentest
• brent geese
• brent goose
• brer
• brere
• breres
• brers
• bresaola
• bresaolas
• bressummer
• bretasche
• bretesse
• brethren
• Breton
• Breton hat
• Bretons
• brettice