slug-a-bed (n.)youdaoicibaDictYouDict[slug-a-bed 词源字典]
also slugabed, 1590s, with bed (n.) + obsolete verb slug "be lazy, intert" (early 15c.), which is perhaps from Scandinavian (see sluggard).[slug-a-bed etymology, slug-a-bed origin, 英语词源]