nefast enfast nfeast fneast efnast fenast neafst enafst naefst anefst eanfst aenfst nfaest fnaest nafest anfest fanest afnest efanst feanst eafnst aefnst faenst afenst nefsat enfsat nfesat fnesat efnsat fensat nesfat ensfat nsefat snefat esnfat senfat nfseat fnseat nsfeat snfeat fsneat sfneat efsnat fesnat esfnat sefnat fsenat sfenat neasft enasft naesft anesft eansft aensft nesaft ensaft nseaft sneaft esnaft senaft naseft anseft nsaeft snaeft asneft saneft easnft aesnft esanft seanft asenft saenft nfaset fnaset nafset anfset fanset afnset nfsaet fnsaet nsfaet snfaet fsnaet sfnaet nasfet ansfet nsafet snafet asnfet sanfet fasnet afsnet fsanet sfanet asfnet safnet efasnt feasnt eafsnt aefsnt faesnt afesnt efsant fesant esfant sefant fseant sfeant easfnt aesfnt esafnt seafnt asefnt saefnt fasent afsent fsaent sfaent asfent safent nefats enfats nfeats fneats efnats fenats neafts enafts naefts anefts eanfts aenfts nfaets fnaets nafets anfets fanets afnets efants feants eafnts aefnts faents afents neftas enftas nfetas fnetas efntas fentas netfas entfas ntefas tnefas etnfas tenfas nfteas fnteas ntfeas tnfeas ftneas tfneas eftnas fetnas etfnas tefnas ftenas tfenas neatfs enatfs naetfs anetfs eantfs aentfs netafs entafs nteafs tneafs etnafs tenafs natefs antefs ntaefs tnaefs atnefs tanefs eatnfs aetnfs etanfs teanfs atenfs taenfs nfates fnates naftes anftes fantes afntes nftaes fntaes ntfaes tnfaes ftnaes tfnaes natfes antfes ntafes tnafes atnfes tanfes fatnes aftnes ftanes tfanes atfnes tafnes efatns featns eaftns aeftns faetns afetns eftans fetans etfans tefans fteans tfeans eatfns aetfns etafns teafns atefns taefns fatens aftens ftaens tfaens atfens tafens nefsta enfsta nfesta fnesta efnsta fensta nesfta ensfta nsefta snefta esnfta senfta nfseta fnseta nsfeta snfeta fsneta sfneta efsnta fesnta esfnta sefnta fsenta sfenta neftsa enftsa nfetsa fnetsa efntsa fentsa netfsa entfsa ntefsa tnefsa etnfsa tenfsa nftesa fntesa ntfesa tnfesa ftnesa tfnesa eftnsa fetnsa etfnsa tefnsa ftensa tfensa nestfa enstfa nsetfa snetfa esntfa sentfa netsfa entsfa ntesfa tnesfa etnsfa tensfa nstefa sntefa ntsefa tnsefa stnefa tsnefa estnfa setnfa etsnfa tesnfa stenfa tsenfa nfstea fnstea nsftea snftea fsntea sfntea nftsea fntsea ntfsea tnfsea ftnsea tfnsea nstfea sntfea ntsfea tnsfea stnfea tsnfea fstnea sftnea ftsnea tfsnea stfnea tsfnea efstna festna esftna seftna fsetna sfetna eftsna fetsna etfsna tefsna ftesna tfesna estfna setfna etsfna tesfna stefna tsefna fstena sftena ftsena tfsena stfena tsfena neastf enastf naestf anestf eanstf aenstf nesatf ensatf nseatf sneatf esnatf senatf nasetf ansetf nsaetf snaetf asnetf sanetf easntf aesntf esantf seantf asentf saentf neatsf enatsf naetsf anetsf eantsf aentsf netasf entasf nteasf tneasf etnasf tenasf natesf antesf ntaesf tnaesf atnesf tanesf eatnsf aetnsf etansf teansf atensf taensf nestaf enstaf nsetaf snetaf esntaf sentaf netsaf entsaf ntesaf tnesaf etnsaf tensaf nsteaf snteaf ntseaf tnseaf stneaf tsneaf estnaf setnaf etsnaf tesnaf stenaf tsenaf nastef anstef nsatef snatef asntef santef natsef antsef ntasef tnasef atnsef tansef nstaef sntaef ntsaef tnsaef stnaef tsnaef astnef satnef atsnef tasnef stanef tsanef eastnf aestnf esatnf seatnf asetnf saetnf eatsnf aetsnf etasnf teasnf atesnf taesnf estanf setanf etsanf tesanf steanf tseanf astenf satenf atsenf tasenf staenf tsaenf nfaste fnaste nafste anfste fanste afnste nfsate fnsate nsfate snfate fsnate sfnate nasfte ansfte nsafte snafte asnfte sanfte fasnte afsnte fsante sfante asfnte safnte nfatse fnatse naftse anftse fantse afntse nftase fntase ntfase tnfase ftnase tfnase natfse antfse ntafse tnafse atnfse tanfse fatnse aftnse ftanse tfanse atfnse tafnse nfstae fnstae nsftae snftae fsntae sfntae nftsae fntsae ntfsae tnfsae ftnsae tfnsae nstfae sntfae ntsfae tnsfae stnfae tsnfae fstnae sftnae ftsnae tfsnae stfnae tsfnae nastfe anstfe nsatfe snatfe asntfe santfe natsfe antsfe ntasfe tnasfe atnsfe tansfe nstafe sntafe ntsafe tnsafe stnafe tsnafe astnfe satnfe atsnfe tasnfe stanfe tsanfe fastne afstne fsatne sfatne asftne saftne fatsne aftsne ftasne tfasne atfsne tafsne fstane sftane ftsane tfsane stfane tsfane astfne satfne atsfne tasfne stafne tsafne efastn feastn eafstn aefstn faestn afestn efsatn fesatn esfatn sefatn fseatn sfeatn easftn aesftn esaftn seaftn aseftn saeftn fasetn afsetn fsaetn sfaetn asfetn safetn efatsn featsn eaftsn aeftsn faetsn afetsn eftasn fetasn etfasn tefasn fteasn tfeasn eatfsn aetfsn etafsn teafsn atefsn taefsn fatesn aftesn ftaesn tfaesn atfesn tafesn efstan festan esftan seftan fsetan sfetan eftsan fetsan etfsan tefsan ftesan tfesan estfan setfan etsfan tesfan stefan tsefan fstean sftean ftsean tfsean stfean tsfean eastfn aestfn esatfn seatfn asetfn saetfn eatsfn aetsfn etasfn teasfn atesfn taesfn estafn setafn etsafn tesafn steafn tseafn astefn satefn atsefn tasefn staefn tsaefn fasten afsten fsaten sfaten asften saften fatsen aftsen ftasen tfasen atfsen tafsen fstaen sftaen ftsaen tfsaen stfaen tsfaen astfen satfen atsfen tasfen stafen tsafen
Note: these 'words' (valid or invalid) are all the permutations of the word nefast. These words are obtained by scrambling the letters in nefast.