duras udras druas rduas urdas rudas duars udars daurs adurs uadrs audrs draus rdaus darus adrus radus ardus urads ruads uards aurds rauds aruds dursa udrsa drusa rdusa urdsa rudsa dusra udsra dsura sdura usdra sudra drsua rdsua dsrua sdrua rsdua srdua ursda rusda usrda surda rsuda sruda duasr udasr dausr adusr uadsr audsr dusar udsar dsuar sduar usdar sudar dasur adsur dsaur sdaur asdur sadur uasdr ausdr usadr suadr asudr saudr drasu rdasu darsu adrsu radsu ardsu drsau rdsau dsrau sdrau rsdau srdau dasru adsru dsaru sdaru asdru sadru rasdu arsdu rsadu sradu asrdu sardu urasd ruasd uarsd aursd rausd arusd ursad rusad usrad surad rsuad sruad uasrd ausrd usard suard asurd saurd rasud arsud rsaud sraud asrud sarud
Note: these 'words' (valid or invalid) are all the permutations of the word duras. These words are obtained by scrambling the letters in duras.