Yes, CHAD is a Scrabble word!

Letter values in Scrabble US: C 3, H 4, A 1, D 2.

Is it a valid word?

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

a small piece of paper that is supposed to be removed when a hole is punched in a card or paper tape
a lake in north central Africa; fed by the Shari river
a landlocked desert republic in north-central Africa; was under French control until 1960
a family of Afroasiatic tonal languages (mostly two tones) spoken in the regions west and south of Lake Chad in north central Africa

Also: lake chad, republic of chad, chadic language.

Not playable in Scrabble US: TCHAD, CHADIC.