Sop

a morsel of bread ( John 13:26 ; Compare Ruth 2:14 ). Our Lord took a piece of unleavened bread, and dipping it into the broth of bitter herbs at the Paschal meal, gave it to Judas. (Compare Ruth 2:14 .)

A little bit; morsel.

When Jesus had thus said, he was troubled in spirit, and testified, and said, Verily, verily, I say unto you, that one of you shall betray me. Then the disciples looked one on another, doubting of whom he spake. Now there was leaning on Jesus' bosom one of his disciples, whom Jesus loved. Simon Peter therefore beckoned to him, that he should ask who it should be of whom he spake. He then lying on Jesus' breast saith unto him, Lord, who is it? Jesus answered, He it is, to whom I shall give a SOP, when I have dipped it. And when he had dipped the SOP, he gave it to Judas Iscariot, the son of Simon. ( John 13:21-26 )

In eastern lands where our table utensils are unknown, the meat, with the broth, is brought upon the table in a large dish, and is eaten usually by means of pieces of bread clipped into the common dish. The bread so dipped is called. "It was such a piece of bread a sop dipped in broth that Jesus gave to Judas, ( John 13:26 ) and again, in Matt 26:23 it is said "he that dippeth his hand with me in the dish," i.e. to make a sop by dipping a piece of bread into the central dish. [E] indicates this entry was also found in Easton's Bible Dictionary

SOP

sop (psomion):

A thin, wafer-like piece of bread dipped into the common dish as a sort of improvised spoon, is thus designated in John 13:26.

See MORSEL.