Is “Annex” a Scrabble word?
Yes
ANNEX
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Annex
/ˈænɛks/
noun
1.An addition, an extension.
2.An appendix to a book or document.
3.An addition or extension to a building.