The word 'afkoman' is of Greek derivation, according to some authorities from ἐπὶ κῶμον (epikohmon) - a call for the after-dinner pastime (κῶμον) - or the ἐπικώμιον (epikomion, festal song).  This is the final part of the seder meal.

The Hebrew word for this part of the seder, tzafun, means 'hidden', because now is the time to eat the larger piece of the middle matzah that was hidden earlier - the afikoman.  Each person at the seder table receives a piece. The Afikoman will be the last thing we eat tonight, and we should let the taste of this bread of affliction and bread of freedom linger in our mouths.

Eat at least a kezayit of the afikoman in the reclining position.

haggadah Section: Tzafun