“QUITTOR” is a valid word. — 16 points Scrabble

tutora person who gives private instruction (as in singing, acting, etc.)
troutflesh of any of several primarily freshwater game and food fishes
quirtwhip with a leather thong at the end
quoitgame equipment consisting of a ring of iron or circle of rope used in playing the game of quoits

quitput an end to a state or an activity
toura journey or route all the way around a particular place or area
riota public act of violence by an unruly mob
toria ring-shaped surface generated by rotating a circle around an axis that does not intersect the circle
trota slow pace of running
triothe cardinal number that is the sum of one and one and one
toutsomeone who buys tickets to an event in order to resell them at a profit
routa disorderly crowd of people
roti
tort(law) any wrongdoing for which an action for damages may be brought
toit
tirosomeone new to a field or activity

out(baseball) a failure by a batter or runner to reach a base safely in baseball
our
rota state of decay usually accompanied by an offensive odor
titeither of two soft fleshy milk-secreting glandular organs on the chest of a woman
ruta groove or furrow (especially one in soft earth caused by wheels)
tora prominent rock or pile of rocks on a hill
tututter `tsk,' `tut,' or `tut-tut,' as in disapproval
tota small amount (especially of a drink)
tui
ort

to
itthe branch of engineering that deals with the use of computers and telecommunications to retrieve and store and transmit information
ora state in northwestern United States on the Pacific
qi
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
utthe local time at the 0 meridian passing through Greenwich, England; it is the same everywhere

QUITTOR