“SIXTYISH” is a valid word. — 21 points Scrabble

this
shitobscene terms for feces
hits(baseball) a successful stroke in an athletic contest (especially in baseball)
sitsbe seated
hissa fricative sound (especially as an expression of disapproval)
sith
hist
xyst

his
sitbe seated
its
hit(baseball) a successful stroke in an athletic contest (especially in baseball)
sixthe cardinal number that is the sum of five and one
thy
shya quick throw
sisa female person who has the same parents as another person
tis
styan infection of the sebaceous gland of the eyelid
xis

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)
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
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

SIXTYISH