litteryoudaoicibaDictYouDict[litter 词源字典]
litter: [13] The word litter has come a long way semantically since it was born, from ‘bed’ to ‘rubbish scattered untidily’. It goes back ultimately to Latin lectus ‘bed’, a distant relative of English lie and source of French lit ‘bed’ (which forms the final syllable of English coverlet [13], etymologically ‘bed-cover’). From lectus was derived medieval Latin lectāria, which passed into English via Old French litiere and Anglo-Norman litere ‘bed’.

This original sense was soon extended in English to a ‘portable conveyance or stretcher’, which still survives, just, as an archaism, but the word’s main modern sense, which first emerged fully in the 18th century, derives from the notion of scattering straw over the floor for bedding.
=> coverlet[litter etymology, litter origin, 英语词源]
litter (n.)youdaoicibaDictYouDict
c. 1300, "a bed," also "bed-like vehicle carried on men's shoulders" (early 14c.), from Anglo-French litere "portable bed," Old French litiere "litter, stretcher, bier; straw, bedding," from Medieval Latin lectaria "litter" (altered in French by influence of lit "bed"), from Latin lectus "bed, couch," from PIE *legh-to-, from root *legh- "to lie" (see lie (v.2)).

Meaning extended early 15c. to "straw used for bedding" (early 14c. in Anglo-French) and late 15c. to "offspring of an animal at one birth" (in one bed); sense of "scattered oddments, disorderly debris" is first attested 1730, probably from Middle English verb literen "provide with bedding" (late 14c.), with notion of strewing straw. Litter by 19c. had come to mean both the straw bedding and the animal waste in it after use.
litter (v.)youdaoicibaDictYouDict
late 14c., "provide with bedding," from litter (n.). Meaning "to strew with objects" is from 1713. Transitive sense of "to scatter in a disorderly way" is from 1731. Related: Littered; littering.