pret. dugði; pres. dugi; sup. dugat; imperat. dugi þú, mod. dugðu; [A. S. dugan; Scot. and North. E. to dow; O. H. G. tûgan; Germ. taugen: Dan. due; Swed. duga; Engl. do, in phrases such as, that will do]:—to help, aid, with dat.; dugi þú mér Hvíta-Kristr, Fs. 101; d. frændum sínum, Post. 658 C. 19; ok vill eigi d. henni, will not support her, Grág. i. 368; hann dugði heiðnum mönnum, 655 iii. 4: with the notion to do, suffice, þat er þér man d., which will do for thee, Nj. 13; hefir oss þó dugat þessi átrúnaðr, this faith has done well for us, Fms. i. 34; mun þat d. mínum hesti, it will do for my horse, Mag.: the proverb, fátt er svá illt at einu-gi dugi, cp. the Engl. ‘’tis an ill wind that blows nobody good,’ Al. 46, Hm. 134; mun þér eigi þat d. at sofa hér, it will not do (is not safe) for thee to sleep here, Fms. v. 307: adding prepp. við, at, til, to succour, lend help, en Gísli fór at d. þeim við, Gísl. 22; d. þeir nú at þeim mönnum er lífs var van, Finnb. 316, cp. at-dugnaðr; hón dugir eigi verr til enn einhverr karlmaðr, Fb. i. 533: impers., e-m dugir e-t, it does well, beseems, becomes; hón dugir mér illa (vel), Mar. (Fr.), Hkv. I. 45; þó myndi mér enn vel d. (it would do well for me), ef ek fengja at drekka, Ísl. ii. 369.

β. absol. or even neut. to shew prowess, do one’s best; dugi þú enn, help! Fms. ii. 75; dugði hverr sem mátti, every one did his best, viii. 139; dugi nú hverr sem drengr er til; mundi þá eigi nauðsyn at d. sem drengilegast, ix. 509: denoting moral force, vel siðaðir menn ok jafnan vel dugat, honest men and who have ever done well, Eg. 96; d. í þurft e-s, Hom. 47.

γ. to suffice, be strong enough; ef þitt æði dugir, if thy wit does suffice, Vþm. 20, 22; ef vitni d., if the witnesses do, i. e. fail not, N. G. L. i. 136; dugði veðr it bezta, the weather did well.