v. 1. To pull off; remove with the fingers. He picked off the burs that had stuck to his overcoat. 2. To shoot, one at a time; knock down one by one. The sniper picked off the slower soldiers as they came out into the road. 3. To catch a base runner off base by throwing the ball quickly to a fielder who tags him out. The pitcher turned around suddenly and threw to the second baseman to pick the runner off second base.
Compare: OFF BASE. 4. To catch and, especially in football, to intercept. Alert defenders picked off three of Jack's passes.