Language (dialektōi). Not a dialect of the Greek, but a different language, the Aramaic. So also in Act 2:6; Act 21:40. Dialektos is from dialegomai, to converse, to speak between two (dia).
Akeldama (Hakeldamach). This Aramaic word Peter explains as “the field of blood.” Two traditions are preserved: one in Mat 27:7 which explains that the priests purchased this potter’s field with the money which Judas flung down as the price of the blood of Jesus. The other in Acts describes it as the field of blood because Judas poured out his blood there. Hackett and Knowling argue that both views can be true. “The ill-omened name could be used with a double emphasis” (Hackett).