xi /zī, ksī or ksē/

1. The fourteenth letter of the Greek alphabet (Ξ or ξ), corresponding to X
2. As a numeral ξˈ = 60, ˌξ = 60000

• ball-gowns
• ballhawk
• ballhawks
• balling
• ballings
• ballista
• ballistae
• ballistas
• ballistic
• ballistic missile
• ballistic missiles
• ballistic pendulum
• ballistic pendulums
• ballistics
• ballistite
• ballistites
• ballistocardiogram
• ballistocardiograms
• ballistocardiograph
• ballistocardiography
• ballium
• balliums
• ball lightning
• ball mill
• ball mills