(idiomatic) Alert, active, or attentive; on top of things.
If I had been more on the ball I would have asked when he called me.
(sports) Being in control of the ball.
(Australian rules football) Playing as a midfielder.
Source: en.wiktionary.orgAccording to the universal property, there exists a unique extension βa: βN → B. This extension does not depend on the ball B we consider. Source: Internet
Another statement of purpose; "United we stand, divided we fall, come on people, let's get on the ball." Source: Internet
A small portion of exploding gas also escapes through the vent, but this does not dramatically affect the total force exerted on the ball. Source: Internet
A certain use of the foot on the ball which had the same effect as heeling it back was known as a "snap". Source: Internet
Another wicket taking method was to impart more spin on the ball than usual, and surprise the batsman. Source: Internet
A spin bowler usually delivers the ball quite slowly and puts spin on the ball, causing it to turn at an angle while bouncing off the pitch. Source: Internet