stmah tsmah smtah mstah tmsah mtsah stamh tsamh satmh astmh tasmh atsmh smath msath samth asmth masth amsth tmash mtash tamsh atmsh matsh amtsh stmha tsmha smtha mstha tmsha mtsha sthma tshma shtma hstma thsma htsma smhta mshta shmta hsmta mhsta hmsta tmhsa mthsa thmsa htmsa mhtsa hmtsa stahm tsahm sathm asthm tashm atshm stham tsham shtam hstam thsam htsam sahtm ashtm shatm hsatm ahstm hastm tahsm athsm thasm htasm ahtsm hatsm smaht msaht samht asmht masht amsht smhat mshat shmat hsmat mhsat hmsat sahmt ashmt shamt hsamt ahsmt hasmt mahst amhst mhast hmast ahmst hamst tmahs mtahs tamhs atmhs maths amths tmhas mthas thmas htmas mhtas hmtas tahms athms thams htams ahtms hatms mahts amhts mhats hmats ahmts hamts
Note: these 'words' (valid or invalid) are all the permutations of the word stmah. These words are obtained by scrambling the letters in stmah.