derns edrns drens rdens erdns redns denrs ednrs dners nders endrs nedrs drnes rdnes dnres ndres rndes nrdes ernds rends enrds nerds rneds nreds dersn edrsn dresn rdesn erdsn redsn desrn edsrn dsern sdern esdrn sedrn drsen rdsen dsren sdren rsden srden ersdn resdn esrdn serdn rsedn sredn densr ednsr dnesr ndesr endsr nedsr desnr edsnr dsenr sdenr esdnr sednr dnser ndser dsner sdner nsder snder ensdr nesdr esndr sendr nsedr snedr drnse rdnse dnrse ndrse rndse nrdse drsne rdsne dsrne sdrne rsdne srdne dnsre ndsre dsnre sdnre nsdre sndre rnsde nrsde rsnde srnde nsrde snrde ernsd rensd enrsd nersd rnesd nresd ersnd resnd esrnd sernd rsend srend ensrd nesrd esnrd senrd nserd snerd rnsed nrsed rsned srned nsred snred
Note: these 'words' (valid or invalid) are all the permutations of the word derns. These words are obtained by scrambling the letters in derns.