frodil
The longest words are 5 letters: fetid and tepid.
Some words that use the letters 'd u n e f o u' are:dendodueduneendeonfeudfoefondfonduefoundfunfundnonodnudeodeofononeundoundue
Honed
88.fruitedriftedturfeddriftfetidfiredfriedfruitrefittiredtriedtrueduteridefideftdietdiredirtditeduetduitdureeditetuifeudfirefretfritiredreftreifrideriferiftriteruderuedtidetiedtiertiretreftrueturdturfdefdiedifditdueduieftfedferfetfeufidfiefirfitfudfurireredrefreiretridrifrueruttedtietuiurdutedeedeferetfeidifitretiut
The letters do not spell any 10 letter words. However, they can be used to spell the 6 letter afraid.
The biggest word I get is fondue, and some smaller words:dendodoedondoneduedunduneduoedendeonfedfenfendfeudfoefondfoundfunfundnonodnodenudeodeofononeundoundueunfed
These are the initial letters of the months of the year, January, February . . .etc.
FaceCafeAce
Cod. Lot, and Dot. Thats all I have so far.
The letters can be used to spell the 7 letter words alfredo, floored, formula and leopard. They also spell paroled, preload and proofed.
HI, of, Is,
HiRatHatFatFitHitHair