4 letters · 6 points in Scrabble
noun a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar
originFrom Latin apsis, hapsis, from Ancient Greek ἁψίς (hapsís, “arch, vault”), from ἅπτω (háptō, “to bind, join”).
Etymology from Wiktionary, CC BY-SA 3.0