early 15c., "idle one's time, dawdle over work;" perhaps from or akin to Middle Dutch loteren "be loose or erratic, shake, totter" like a loose tooth or a sail in a storm; in modern Dutch, leuteren "to delay, linger, loiter over one's work," according to Watkins, literally "to make smaller," and perhaps from Germanic *lut-, from PIE *leud- "small" (see little (adj.)).
The Dutch word is said to be cognate with Old English lutian "lurk," and related to Old English loddere "beggar;" Old High German lotar "empty, vain," luzen "lurk;" German Lotterbube "vagabond, rascal," lauschen "eavesdrop;" Gothic luton "mislead;" Old English lyðre "base, bad, wicked." Related: Loitered; loitering.