INSIDIOUS

Yes, INSIDIOUS is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, S 1, I 1, D 2, I 1, O 1, U 1, S 1.I 1 · N 1 · S 1 · I 1 · D 2 · I 1 · O 1 · U 1 · S 1

Is it a valid word?

• Scrabble US: valid, 10 points.Scrabble USYour dictionary · Change (go to the dictionary switch)Valid · 10 points
• Scrabble UK: valid, 10 points. Make Scrabble UK your dictionary.Scrabble UKYour dictionary · ChangeValid · 10 points
• Words with Friends: valid, 12 points. Make Words with Friends your dictionary.Words with FriendsYour dictionary · ChangeValid · 12 points