7 letters · 11 points in Scrabble
noun the 15th letter of the Greek alphabet
originFrom Latin omicron, from Koine Greek ὂ μῑκρόν (ò mīkrón, “little o”), named in contrast with omega (“big o”). The uncommon form omicra is similarly borrowed from Latin and Greek. The use for designating stars in a constellation—typically in order of apparent brightness—began with Johann Bayer's 1603 Uranometria.
Etymology from Wiktionary, CC BY-SA 3.0