nugtr ungtr ngutr gnutr ugntr guntr nutgr untgr ntugr tnugr utngr tungr ngtur gntur ntgur tngur gtnur tgnur ugtnr gutnr utgnr tugnr gtunr tgunr nugrt ungrt ngurt gnurt ugnrt gunrt nurgt unrgt nrugt rnugt urngt rungt ngrut gnrut nrgut rngut grnut rgnut ugrnt gurnt urgnt rugnt grunt rgunt nutrg untrg nturg tnurg utnrg tunrg nurtg unrtg nrutg rnutg urntg runtg ntrug tnrug nrtug rntug trnug rtnug utrng turng urtng rutng trung rtung ngtru gntru ntgru tngru gtnru tgnru ngrtu gnrtu nrgtu rngtu grntu rgntu ntrgu tnrgu nrtgu rntgu trngu rtngu gtrnu tgrnu grtnu rgtnu trgnu rtgnu ugtrn gutrn utgrn tugrn gturn tgurn ugrtn gurtn urgtn rugtn grutn rgutn utrgn turgn urtgn rutgn trugn rtugn gtrun tgrun grtun rgtun trgun rtgun
Note: these 'words' (valid or invalid) are all the permutations of the word nugtr. These words are obtained by scrambling the letters in nugtr.