To be surprised off guard, taken unawares. This term began life in the sixteenth century as to be taken napping. “Take Nappynge as Mosse toke his Meare” was the title of a 1569 ballad. The term was included in John Ray’s proverb collection of 1670, in which Ray commented, “Who this Moss was is not very material to know. I suppose some such man might find his mare dead, and taking her to be only asleep, might say, ‘Have I caught you napping?’” Yet Shakespeare and other sixteenth-century writers used the phrase in the modern sense of taking someone unawares; “Nay, I have ta’en you napping, gentle love,” Tranio says to Bianca (The Taming of the Shrew, 4.2).