2、lazy:  Lazy is one of the problem words of English. It suddenly appears in the middle of the 16th century, and gradually replaces the native terms slack, slothful, and idle as the main word for expressing the concept ‘averse to work’, but no one knows for sure where it came from. Early spellings such as laysy led 19th-century etymologists to speculate that it may have been derived from lay, but the more generally accepted theory nowadays is that it was borrowed from Low German. Middle Low German had the similar lasich ‘lazy, loose’, which may go back to an Indo-European form denoting ‘slack’.
4、1540s, laysy, of unknown origin. Replaced native slack, slothful, and idle as the main word expressing the notion of"averse to work."In 19c. thought to be from lay (v.) as tipsy from tip. Skeat is responsible for the prevailing modern view that it probably comes from Low German, from a source such as Middle Low German laisch"weak, feeble, tired,"modern Low German läösig, early modern Dutch leuzig, all of which may go back to the PIE root *(s)leg-"slack."According to Weekley, the -z- sound disqualifies a connection with French lassé"tired"or German lassig"lazy, weary, tired."A supposed dialectal meaning"naught, bad,"if it is the original sense, may tie the word to Old Norse lasenn"dilapidated,"lasmøyrr"decrepit, fragile,"root of Icelandic las-furða"ailing,"las-leiki"ailment."Lazy Susan is from 1917. Grose ("Dictionary of the Vulgar Tongue,"1788) has Lazy Man's Load:"Lazy people frequently take up more than they can safely carry, to save the trouble of coming a second time."