Is “Ortho” a Scrabble word?
Yes
ORTHO
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Ortho
noun
1.An isomer of a benzene derivative having two substituents adjacent on the ring.
2.A certain type of flat eyepiece.
3.An orthochromatic plate.