[3] sumr (m.) ‘the swim’: A hap. leg. Perhaps from the strong verb svimma ‘swim’ (cf. New Norw. sum ‘swam’, Shetland Norn sum ‘flood, swimming’), or else related to ODan. sum ‘quiet’ (see AEW: sumr; ÍO: sum(u)r 1). If the latter, sumr would mean ‘calm one’ (cf. sílægja ‘ever-lying one’, l. 1 above and the next heiti, lœgir ‘calm one’, derived from the strong verb liggja ‘lie’).