1. An unstable meson produced as the result of a high-energy particle collision
   - kaon, kappa-meson, k-meson

Type of: meson, mesotron

• Roland de Lassus
• Rolando's area
• Rolando's fissure
• role
• role model
• role player
• role-playing game
• roleplay
• roleplaying
• Rolf
• roll
• roll around
• roll call
• roll down
• roll film
• roll in
• roll in the hay
• roll of tobacco
• roll off
• roll out
• roll up
• roll-on
• roll-on roll-off
• roll-top
• roll-top desk