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

• reconnoitre
• reconnoitred
• reconnoitrer
• reconnoitrers
• reconnoitres
• reconnoitring
• reconquer
• reconquered
• reconquering
• reconquers
• reconquest
• reconquests
• recons
• reconsecrate
• reconsecrated
• reconsecrates
• reconsecrating
• reconsecration
• reconsecrations
• reconsider
• reconsideration
• reconsidered
• reconsidering
• reconsiders
• reconsolidate