“UNMIXT” is a valid word. — 15 points Scrabble

mixa commercially prepared mixture of dry ingredients
nutusually large hard-shelled seed
tina silvery malleable metallic element that resists corrosion; used in many alloys and to coat other metals to prevent corrosion; obtained chiefly from cassiterite where it occurs as tin oxide
tuxsemiformal evening dress for men
nimgame in which matchsticks are arranged in rows and players alternately remove one or more of them; in some versions the object is to take the last remaining matchstick on the table and in other versions the object is to avoid taking the last remaining matchstick on the table
mun
nixa quantity of no importance
tui
nita luminance unit equal to 1 candle per square meter measured perpendicular to the rays from the source
tuna large cask especially one holding a volume equivalent to 2 butts or 252 gals
mut

itthe branch of engineering that deals with the use of computers and telecommunications to retrieve and store and transmit information
ina unit of length equal to one twelfth of a foot
um
midestruction of heart tissue resulting from obstruction of the blood supply to the heart muscle
unan organization of independent states formed in 1945 to promote international peace and security
muthe 12th letter of the Greek alphabet
xithe cardinal number that is the sum of ten and one
tia light strong grey lustrous corrosion-resistant metallic element used in strong lightweight alloys (as for airplane parts); the main sources are rutile and ilmenite
xu
nuthe 13th letter of the Greek alphabet
utthe local time at the 0 meridian passing through Greenwich, England; it is the same everywhere

UNMIXT