8 letters · 14 points in Scrabble
adjective instructive (especially excessively)
originFrom French didactique, from Ancient Greek διδακτικός (didaktikós, “skilled in teaching”), from διδακτός (didaktós, “taught, learnt”), from διδάσκω (didáskō, “to teach, educate”). By surface analysis, didact + -ic.
Etymology from Wiktionary, CC BY-SA 3.0