grein rgein gerin egrin regin ergin grien rgien giren igren rigen irgen geirn egirn giern igern eigrn iegrn reign erign riegn iregn eirgn iergn greni rgeni gerni egrni regni ergni grnei rgnei gnrei ngrei rngei nrgei genri egnri gneri ngeri engri negri rengi erngi rnegi nregi enrgi nergi grine rgine girne igrne rigne irgne grnie rgnie gnrie ngrie rngie nrgie ginre ignre gnire ngire ingre nigre ringe irnge rnige nrige inrge nirge geinr eginr gienr igenr eignr iegnr genir egnir gneir ngeir engir negir giner igner gnier ngier inger niger eingr iengr enigr neigr inegr niegr reing ering rieng ireng eirng ierng renig ernig rneig nreig enrig nerig rineg irneg rnieg nrieg inreg nireg einrg ienrg enirg neirg inerg nierg
Note: these 'words' (valid or invalid) are all the permutations of the word grein. These words are obtained by scrambling the letters in grein.