Yes, HYPERMEDIA is a Scrabble word!

Letter values in Scrabble US: H 4, Y 4, P 3, E 1, R 1, M 3, E 1, D 2, I 1, A 1.

Is it a valid word?

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

a multimedia system in which related items of information are connected and can be presented together

Also: hypermedia system, interactive multimedia, interactive multimedia system.