ertar retar etrar terar rtear trear eratr reatr eartr aertr raetr aretr etarr tearr eatrr aetrr taerr aterr rtaer traer rater arter tarer atrer ertra retra etrra terra rtera trera errta rerta errta rerta rreta rreta etrra terra ertra retra trera rtera rtrea trrea rrtea rrtea trrea rtrea erart reart earrt aerrt raert arert errat rerat errat rerat rreat rreat earrt aerrt erart reart arert raert raret arret rraet rraet arret raret etarr tearr eatrr aetrr taerr aterr etrar terar ertar retar trear rtear eartr aertr eratr reatr aretr raetr tarer atrer traer rtaer arter rater rtare trare ratre artre tarre atrre rtrae trrae rrtae rrtae trrae rtrae rarte arrte rrate rrate arrte rarte tarre atrre trare rtare artre ratre
Note: these 'words' (valid or invalid) are all the permutations of the word ertar. These words are obtained by scrambling the letters in ertar.