“STIFFISH” is a valid word. — 17 points Scrabble

this
shitobscene terms for feces
fishany of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
hits(baseball) a successful stroke in an athletic contest (especially in baseball)
fitsa display of bad temper
fista hand with the fingers clenched in the palm (as for hitting)
sitsbe seated
hissa fricative sound (especially as an expression of disapproval)
tiffa quarrel about petty points
siftmove as if through a sieve
sith
hist

his
sitbe seated
its
hit(baseball) a successful stroke in an athletic contest (especially in baseball)
fita display of bad temper
sisa female person who has the same parents as another person
tis
ifs
iff

itthe branch of engineering that deals with the use of computers and telecommunications to retrieve and store and transmit information
ishave the quality of being; (copula, used with an adjective or a predicate noun)
if
hian expression of greeting
sia tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
sh
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

STIFFISH