mal — de Vaan
mal 'stagnant water', OPr. mary, Lith. mares < *moria7 OCS morjey Ru. more [n.], morja [nom.pL] < *morio-> Go. mari-saihws, OIc. marr 'sea', OHG mari, men 'sea, lake'. Mare has resulted from unrounding of *mo- in open syllable. The adj. mariscus is considerd to be obscure, but may well be a derivative of mare. Note that *mor-ireferred to any large body of water, e.g. a lake. Lat. mari-timus may have been modelled … — [de Vaan, s.v. mal, p. 379]