Aceldama was the Aramaic name given to the field that was purchased with the bribe money that had been given to Judas Iscariot for betraying Jesus Christ. Previously known as "the potter's field" when it was used as a burial place for indigent transients, Aceldama means "field of blood" - a name that is based on that Judas' plot there was purchased with the "blood money" that he received for betraying the Messiah (and also, perhaps, at least partly because of the gory condition of Judas' body when it was buried there, i.e. Acts 1:18). Aceldama is located on a narrow terrace on the south face of the Valley Of Hinnom; perhaps as no coincidence, Judas' dead body (see What Happens When You Die?) went to "hell" on the day that he died (see Where Is Hell?).
"I have sinned in betraying innocent blood"
After Jesus Christ was arrested The Fateful Night, Judas attempted to return the thirty pieces of silver to the chief priests and the elders who had given it to him for his betrayal of the Messiah, but they refused to accept it:
"When morning came, all the chief priests and the elders of the people took counsel against Jesus to put Him to death; and they bound Him and led Him away and delivered Him to Pilate the governor.
"When Judas, His betrayer, saw that He was condemned, He repented and brought back the thirty pieces of silver to the chief priests and the elders, saying, "I have sinned in betraying innocent blood."
They said, "What is that to us? See to it yourself."
And throwing down the pieces of silver in the Temple, he departed; and he went and hanged himself.
But the chief priests, taking the pieces of silver, said, "It is not lawful to put them into the treasury, since they are blood money." So they took counsel, and bought with them the potter's field, to bury strangers in. Therefore that field has been called the Field of Blood to this day. Then was fulfilled what had been spoken by the prophet Jeremiah, saying, "And they took the thirty pieces of silver, the price of him on whom a price had been set by some of the sons of Israel, and they gave them for the potter's field, as the Lord directed me." (Matthew 27:1-10 RSV)
As Matthew 27:9-10 plainly states, Judas' betrayal of the Christ was prophesied centuries before by the prophet Jeremiah. It was also written by King David in the Psalms:
"In those days Peter [see also Peter's Ministry] stood up among the brethren, the company of persons was in all about a hundred and twenty, and said, "Brethren, the Scripture had to be fulfilled, which the Holy Spirit spoke beforehand by the mouth of David, concerning Judas who was guide to those who arrested Jesus. For he was numbered among us, and was allotted his share in this ministry.
Now this man bought a field with the reward of his wickedness; and falling headlong he burst open in the middle and all his bowels gushed out. And it became known to all the inhabitants of Jerusalem, so that the field was called in their language Akeldama, that is, Field of Blood. For it is written in the book of Psalms, 'Let his habitation become desolate, and let there be no one to live in it'; and 'His office let another take.'
So one of the men who have accompanied us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John [see The Origin of Baptism] until the day when He was taken up from us - one of these men [see Matthias] must become with us a witness to his resurrection." (Acts 1:15-22 RSV)
Fact Finder: Why did Jesus Christ die the way that He did?
See Why Blood?