rumba urmba rmuba mruba umrba murba rubma urbma rbuma bruma ubrma burma rmbua mrbua rbmua brmua mbrua bmrua umbra mubra ubmra bumra mbura bmura rumab urmab rmuab mruab umrab murab ruamb uramb raumb arumb uarmb aurmb rmaub mraub ramub armub marub amrub umarb muarb uamrb aumrb maurb amurb rubam urbam rbuam bruam ubram buram ruabm urabm raubm arubm uarbm aurbm rbaum braum rabum arbum barum abrum ubarm buarm uabrm aubrm baurm aburm rmbau mrbau rbmau brmau mbrau bmrau rmabu mrabu rambu armbu marbu amrbu rbamu bramu rabmu arbmu barmu abrmu mbaru bmaru mabru ambru bamru abmru umbar mubar ubmar bumar mbuar bmuar umabr muabr uambr aumbr maubr amubr ubamr buamr uabmr aubmr baumr abumr mbaur bmaur mabur ambur bamur abmur
Note: these 'words' (valid or invalid) are all the permutations of the word rumba. These words are obtained by scrambling the letters in rumba.