An Etymological Dictionary of the German Language/schwelgen
schwelgen, vb. ‘to guzzle, carouse, revel,’ from MidHG. swëlgen, swëlhen, ‘to swallow, gulp down, drink,’ OHG. swëlgan, swëlahan, ‘to swallow, gulp down’; comp. OSax. far-swëlgan, ‘to gulp down,’ Du. zwelgen, ‘to swallow,’ zwelg, ‘draught,’ AS. swëlgan, E. to swallow, OIc. svelgja, ‘to swallow’; Goth. *swilhan is wanting. A Teut. root. swëlh (swëlg by grammatical change), from pre-Teut. swelk, is not found elsewhere. See Schwalch.