Yes, DEVELOPMENT is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, V 4, E 1, L 1, O 1, P 3, M 3, E 1, N 1, T 1.

Is it a valid word?

DEVELOPMENT is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

act of improving by expanding or enlarging or refining
a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)
(biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level
a recent event that has some relevance for the present situation
the act of making some area of land or water more profitable or productive or useful
a district that has been developed to serve some purpose
a state in which things are improving; the result of developing (as in the early part of a game of chess)
processing a photosensitive material in order to make an image visible
(music) the section of a composition or movement (especially in sonata form) where the major musical themes are developed and elaborated