spend psend sepnd espnd pesnd epsnd spned psned snped nsped pnsed npsed senpd esnpd snepd nsepd enspd nespd pensd epnsd pnesd npesd enpsd nepsd spedn psedn sepdn espdn pesdn epsdn spden psden sdpen dspen pdsen dpsen sedpn esdpn sdepn dsepn edspn despn pedsn epdsn pdesn dpesn edpsn depsn spnde psnde snpde nspde pnsde npsde spdne psdne sdpne dspne pdsne dpsne sndpe nsdpe sdnpe dsnpe ndspe dnspe pndse npdse pdnse dpnse ndpse dnpse sendp esndp snedp nsedp ensdp nesdp sednp esdnp sdenp dsenp edsnp desnp sndep nsdep sdnep dsnep ndsep dnsep endsp nedsp ednsp densp ndesp dnesp pends epnds pneds npeds enpds nepds pedns epdns pdens dpens edpns depns pndes npdes pdnes dpnes ndpes dnpes endps nedps ednps denps ndeps dneps
Note: these 'words' (valid or invalid) are all the permutations of the word spend. These words are obtained by scrambling the letters in spend.