kaupir, pret. keypti, part. keypt; [Ulf. kaupatjan = κολαφίζειν and kaupon = πραγματεύεσθαι, Luke xix. 13; A. S. ceâpian; Old Engl. chop; North. E. coup; cp. Engl. cheapen, chaffer, couper, chap-man, etc. (see angr); Germ. kaufen; Dutch koopen; Swed. köpa; Dan. kjöbe; a word common to all Teut. languages. The derivation from Lat. caupona is hardly admissible, whereas Grimm’s ingenious suggestion (Dict. iii. 198) connecting it with Goth. kaupatjan, which Ulf. uses = to strike in the face, is strongly borne out by the very form of the Icel. word;—since, first, this word, although having au as its root vowel, follows the 2nd and not the 1st weak conjugation; secondly, the vowel changes in preterite and participle, which is characteristic of a verb with an inflexive or characteristic j; thirdly, the t in the preterite (so far as is known) is never spelt with ð or þ,—keypti, not keypði or keypþi (see introduction to letter D, C. III. 2),—which indicates that the t is here radical and not inflexive. The Icel. word therefore represents in its tenses both the Gothic words,—kaupan in the present tense, kaupatjan in the preterite: the bargain was symbolized by ‘striking,’ hence the phrase ‘to strike’ a bargain, Dutch koopslagen.]

B. To buy; magran mar kaupa, Hm. 83; kaupa frið, Skm. 19; opt kaupir sér í litlu lof, Hm. 51; vel-keyptr, 107; allan þann varning er þú kaupir ok selr, Sks. 20; hann keypti skip til ferðar, Mar. passim; keypti Njáll land í Ossabæ, Nj. 151, Grág. ii. 243; Vill Rútr görask mágr þinn ok kaupa dóttur þína, Nj. 3:—the bargain or price in dat., skal öln (dat.) kaupa geymslu á kú, Grág. i. 147, 466; kaupa land verði, ii. 243; k. sex álnum, i. 466; kaupa mey (konu) mundi, þá er kona mundi keypt, er mörk sex álna aura er goldin at mundi eðr handsöluð, eðr meira fé ella, 175; gulli keypta léztú Gýmis dóttur, Ls. 42.

2. absol. to make a bargain; þótt vér kaupim eigi, Nj. 49: kaupa kaupi, to bargain; eigi kemr mér þat í hug at Snorri kaupi sínu kaupi betr þótt hann gefi þér mat, Eb. 182; k. dýrt, to buy dearly, metaph., Parc., Str. 50.

II. with prepp.; kaupa saman, to bargain, Hkv. Hjörv. 3; kaupa á braut, to buy one off; þess væntir mik, at þú sér vel þessu á braut kaupandi, well worth being bought off at this price, Fms. xi. 56:—k. við e-n, to make a bargain, come to terms with one, Nj. 40, Fb. ii. 75:—k. um, to barter, exchange; keypti hann um lönd við Guðrúnu Ósvífrs-dóttur, Eb. 282; kaupa klæðum (klæði um?) við e-n, to exchange clothes with one, Fms. ii. 156; mælt var at þau mundi kaupa um lönd, Snorri ok Guðrún, Ld. 248; drottning keypti um sonu við ambátt, Fas. ii. 59:—k. e-t at e-m, to buy of one; hann keypti at Þorgeiri, Íb. 11 (cꜹpti MS.); þat er mitt eyrendi at k. at þér kvikfé, Fms. vi. 103, Ld. 96, Fb. ii. 75.

III. reflex., rétt er at maðr láti kaupask verk at, hire oneself out, Grág. i. 468: svá mikit sem mér kaupisk í, as much as I gain by it, Band. 31 new Ed.; ef ek vissa, at þat keyptisk í, at …, that it would be gained by it, Fms. v. 138; mikit kaupisk nú í, much is gained, vii. 116; slíkt sem mér kaupisk í, xi. 285.

2. recipr., þar sem menn kaupask saman at lögum, to bargain with one another, Gþl. 477; á þat urðu vit sáttir er vit keyptumk við, Fb. ii. 78; þegar er ér kaupisk við, Eb. 112; öðrumtveggja þeim er við hafa keypzk, Grág. i. 227: the phrase, komask at keyptu, to pay dearly for, smart for it, Eg. 64, Háv. 46, Karl. 401.

3. pass., ekki munu frændr Grettis ausa út fé fyrir verk hans ef honum kaupisk enginn friðr, Grett. 126 A; sem í þessi ferð muni mér þá engi frami kaupask, St. Odd. 10.