1. adj. [wanting in Ulf., who renders βέβαιος etc. by tulgus; but common to all other Teut. idioms; A. S. fæst; Engl. fast; O. H. G. fasti; Germ. fest; Swed.-Dan. fast]:—fast, firm, esp. with the notion of sticking fast to the spot; hrútr f. (held fast, entangled) á meðal viða, 655 vii. 2; fastr á velli, standing fast, e. g. in a battle, Fms. xi. 246; vera, standa f. fyrir, to stand fast, Þorst. St. 53; f. á fótum, of a bondsman whose feet are bound fast to the soil, Grág. ii. 192, Nj. 27: grið-fastr, home-bound, of a servant: the phrase, e-t er fast fyrir, a thing is hard to win, difficult, Lv. 94, Fms. xi. 32, Ld. 154.

β. fast, close; f. í verkum, hard at work, Grág. i. 135 (Ed. 1853); þeir menn allir er í dómi sitja eðr í gögnum eru fastir, engaged, 488; fastr ok fégjarn, close and covetous, Fms. x. 420; f. af drykk, Sturl. iii. 125.

γ. of a meeting; þá er sóknar-þing er fast, i. e. during the session, Grág. i. 422: sam-fastr, fast together, continuous, 156; á-fastr, q. v.

δ. firm; metaph., fast heit, loforð, etc., a fast, faithful promise, word, Eg. 29; föst trú, fast faith, cp. stað-f., steadfast; geð-f., trú-f., vin-f., etc.

ε. bound to pay; at aurum eigi meirum en hann var fastr, to the amount of his debt, N. G. L. i. 36.

ζ. gramm., fast atkvæði, a hard syllable ending in a double consonant, Skálda 171.

2. neut. in various phrases; sitja fast, to sit fast, Sks. 372; standa fast, to stand fast, Edda 33; halda f., to hold fast, Fms. i. 159; binda fast, to bind fast, Ísl. ii. 103, Fas. i. 530; liggja fast, to be fast set, steadfast, of the eyes, Sturl. ii. 189; drekka fast, to drink hard, Fms. ii. 259; sofa fast, to be fast asleep, i. 9; þegja fast, to be dumb, not say a word, 655 xxxi A. 4; leita fast eptir, to urge, press hard, Ld. 322; fylgja fast, to follow fast, Dropl. 26, Fas. ii. 505; eldask fast, to age fast, Eb. 150; ryðjask um fast, to make a hard onslaught, Nj. 9; leggja fast at, to close with one in a sea-fight, Fms. ii. 312, hence fastr bardagi, a close engagement, Róm. 272; telja fast á e-n, to give one a severe lesson, Fms. ii. 119.

β. as adv., hyrndr fast, very much horned, Lv. 69.

γ. the phrase, til fasta, fast, firmly; ráða, mæla, heita til f., to make a firm agreement, Bjarn. 61, Band. 20, Fms. ii. 125; cp. the mod. phrase, fyrir fullt ok fast, definitively.

2. n. the prey of a bear which he drags into his lair; cp. Ivar Aasen s. v. fastra, of a bear, to drag a carcase into his lair (Norse); hence the phrase, liggja á fasti, of a wild beast devouring its prey, Landn. 235 (of a white bear). Icel. now say, liggja á pasti, and in metaph. sense pastr, vigour, energy; pastrs-lauss, weak, feeble, etc.