1. Mentally perceptive and responsive
   - alert, alive, awake 
2. (sports) being in control of the ball

See also: aware, cognisant [Brit], cognizant

Encyclopedia: On the ball, City On the ball

• inauthentic
• inboard
• inborn
• inborn error of metabolism
• inborn reflex
• inbound
• inbred
• inbreed
• inbreeding
• inbuilt
• inc.
• Inca
• incalcitrant
• incalculable
• incalculably
• incalescence
• incalescent
• Incan
• incandesce
• incandescence
• incandescent
• incandescent lamp
• incantation
• incantatory
• incapability