undam nudam udnam dunam nduam dnuam unadm nuadm uandm aundm naudm anudm udanm duanm uadnm audnm daunm adunm ndaum dnaum nadum andum danum adnum undma nudma udnma dunma nduma dnuma unmda numda umnda munda nmuda mnuda udmna dumna umdna mudna dmuna mduna ndmua dnmua nmdua mndua dmnua mdnua unamd nuamd uanmd aunmd naumd anumd unmad numad umnad munad nmuad mnuad uamnd aumnd umand muand amund maund namud anmud nmaud mnaud amnud manud udamn duamn uadmn audmn daumn adumn udman duman umdan mudan dmuan mduan uamdn aumdn umadn muadn amudn maudn damun admun dmaun mdaun amdun madun ndamu dnamu nadmu andmu danmu adnmu ndmau dnmau nmdau mndau dmnau mdnau namdu anmdu nmadu mnadu amndu mandu damnu admnu dmanu mdanu amdnu madnu
Note: these 'words' (valid or invalid) are all the permutations of the word undam. These words are obtained by scrambling the letters in undam.