Definition of "in play" []

• Of a ball (adjective)

WordNet. Princeton University. 2010.

• "The Mk.211 Raufoss is a dedicated armor-piercing .50 caliber round, meant to penetrate light steel, of Norwegian manufacture NAMMO being the name of the firm and design, in play in specialized roles in the American war effort in the Middle East."
• "Is there an armored car in play here that you would know anything—"
• "At first, the ball was signaled in play by left-field umpire Jim Joyce, thus producing a two-run double."