Yes, DEFLEXION is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, F 4, L 1, E 1, X 8, I 1, O 1, N 1.

Is it a valid word?

DEFLEXION is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

the amount by which a propagating wave is bent
the movement of the pointer or pen of a measuring instrument from its zero position
the property of being bent or deflected
a turning aside (of your course or attention or concern)