Yes, ENTERPRISE is a Scrabble word!

Letter values in Scrabble US: E 1, N 1, T 1, E 1, R 1, P 3, R 1, I 1, S 1, E 1.

Is it a valid word?

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

a purposeful or industrious undertaking (especially one that requires effort or boldness)
an organization created for business ventures
readiness to embark on bold new ventures

Also: enterprisingness, go-ahead.