Why do Roman Catholics refer to the Passover as the “Eucharist”?

Since Jesus gave thanks for the bread  (Lk. 22:19) and the wine (Mt 26:27; Mk 14:23; 1Co 11:24) during His final Passover, some have taken the Greek verb “eucharistesas” (“to give thanks”), and the Greek noun “euchariste” (“thanksgiving”), and have created the word “Eucharist.”