merdb emrdb mredb rmedb ermdb remdb medrb emdrb mderb dmerb edmrb demrb mrdeb rmdeb mdreb dmreb rdmeb drmeb erdmb redmb edrmb dermb rdemb dremb merbd emrbd mrebd rmebd ermbd rembd mebrd embrd mberd bmerd ebmrd bemrd mrbed rmbed mbred bmred rbmed brmed erbmd rebmd ebrmd bermd rbemd bremd medbr emdbr mdebr dmebr edmbr dembr mebdr embdr mbedr bmedr ebmdr bemdr mdber dmber mbder bmder dbmer bdmer edbmr debmr ebdmr bedmr dbemr bdemr mrdbe rmdbe mdrbe dmrbe rdmbe drmbe mrbde rmbde mbrde bmrde rbmde brmde mdbre dmbre mbdre bmdre dbmre bdmre rdbme drbme rbdme brdme dbrme bdrme erdbm redbm edrbm derbm rdebm drebm erbdm rebdm ebrdm berdm rbedm bredm edbrm debrm ebdrm bedrm dberm bderm rdbem drbem rbdem brdem dbrem bdrem
Note: these 'words' (valid or invalid) are all the permutations of the word merdb. These words are obtained by scrambling the letters in merdb.