Said of a less-than-alert base-runner who was picked off a base by a quick throw or suddenly caught between bases, or who was otherwise outwitted by the defense.
A quaint but accurate early definition of “baseball napping”: “When a player through carelessness or sleepy-headedness is caught off his base” (Mrs. John A. Logan, Home Manual, 1889). Syn. caught asleep. 1st use. 1860. “[Mattie O’Brien] kept his opponents well on the bases when they reached them. He caught [Frank] Pidgeon napping at first base in capital style” (Brooklyn Eagle, Oct. 30; Peter Morris).