The action or an act of purchasing something. Also: the right to make a purchase. Frequently in "right of (sole) emption" and similar phrases.
Late Middle English (in an earlier sense). From classical Latin emptiōn-, emptiō act of buying, purchasing, thing bought, purchase, deed of purchase from empt-, past participial stem of emere to buy (from the same Indo-European base as Old Church Slavonic imati to seize, collect, Lithuanian imti to take) + -iō.