An Etymological Dictionary of the German Language/gar
gar, adj. (and adv.), ‘finished, ready, done’ (of cooked food), from MidHG. gar (inflect. garwer), adj., gare, adv., OHG. garo (infl. garawêr), adj., garo, garawo, adv., ‘made ready,’ armed, prepared, complete, entire’; corresponding to OSax. garo, AS. gearo (adv., gearwe also), E. yare, Olc. gǫrr (adv. gǫrwa), ‘ready, prepared, made’; Goth. *garwa- is wanting. The adj. was really used as a partic., the suffix wo in Ind., combines with the root pac, ‘to cook,’ forming the partic. pakvâ-s, ‘cooked, done’ (of food). Besides AS. gearo, ‘ready,’ a remarkable form, earo, is found with the same meaning, and in OSax. aru as well as gara; these forms point to Goth. *garwa and *arwa, ‘prepared, made ready.’ Hence some have identified the two classes regarding the g of *garwa- as the remnant of the verbal particle Goth. ga (HG. ge).