lackyoudaoicibaDictYouDict
lack: [12] The word lack is not known to have existed in Old English, although it is by no means impossible that it did. If it was a borrowing, a possible source would have been Middle Dutch lak ‘deficiency, fault’. This has been traced back to a prehistoric Germanic *lak-, a variant of which produced English leak.
=> leak
lack (n.)youdaoicibaDictYouDict
c. 1300, "absence, want; shortage, deficiency," perhaps from an unrecorded Old English *lac, or else borrowed from Middle Dutch lak "deficiency, fault;" in either case from Proto-Germanic *laka- (cognates: Old Frisian lek "disadvantage, damage," Old Norse lakr "lacking"), from PIE *leg- "to dribble, trickle" (see leak (v.)). Middle English also had lackless "without blame or fault."
lack (v.)youdaoicibaDictYouDict
late 12c., perhaps from Middle Dutch laken "to be wanting," from lak (n.) "deficiency, fault," or an unrecorded native cognate word (see lack (n.)). Related: Lacked; lacking.