refund erfund rfeund freund efrund ferund reufnd erufnd ruefnd urefnd eurfnd uerfnd rfuend fruend rufend urfend furend ufrend efurnd feurnd eufrnd uefrnd fuernd ufernd refnud erfnud rfenud frenud efrnud fernud renfud ernfud rnefud nrefud enrfud nerfud rfneud frneud rnfeud nrfeud fnreud nfreud efnrud fenrud enfrud nefrud fnerud nferud reunfd erunfd ruenfd urenfd eurnfd uernfd renufd ernufd rneufd nreufd enrufd nerufd runefd urnefd rnuefd nruefd unrefd nurefd eunrfd uenrfd enurfd neurfd unerfd nuerfd rfuned fruned rufned urfned furned ufrned rfnued frnued rnfued nrfued fnrued nfrued runfed urnfed rnufed nrufed unrfed nurfed funred ufnred fnured nfured unfred nufred efunrd feunrd eufnrd uefnrd fuenrd ufenrd efnurd fenurd enfurd nefurd fneurd nfeurd eunfrd uenfrd enufrd neufrd unefrd nuefrd funerd ufnerd fnuerd nfuerd unferd nuferd refudn erfudn rfeudn freudn efrudn ferudn reufdn erufdn ruefdn urefdn eurfdn uerfdn rfuedn fruedn rufedn urfedn furedn ufredn efurdn feurdn eufrdn uefrdn fuerdn uferdn refdun erfdun rfedun fredun efrdun ferdun redfun erdfun rdefun drefun edrfun derfun rfdeun frdeun rdfeun drfeun fdreun dfreun efdrun fedrun edfrun defrun fderun dferun reudfn erudfn ruedfn uredfn eurdfn uerdfn redufn erdufn rdeufn dreufn edrufn derufn rudefn urdefn rduefn druefn udrefn durefn eudrfn uedrfn edurfn deurfn uderfn duerfn rfuden fruden rufden urfden furden ufrden rfduen frduen rdfuen drfuen fdruen dfruen rudfen urdfen rdufen drufen udrfen durfen fudren ufdren fduren dfuren udfren dufren efudrn feudrn eufdrn uefdrn fuedrn ufedrn efdurn fedurn edfurn defurn fdeurn dfeurn eudfrn uedfrn edufrn deufrn udefrn duefrn fudern ufdern fduern dfuern udfern dufern refndu erfndu rfendu frendu efrndu ferndu renfdu ernfdu rnefdu nrefdu enrfdu nerfdu rfnedu frnedu rnfedu nrfedu fnredu nfredu efnrdu fenrdu enfrdu nefrdu fnerdu nferdu refdnu erfdnu rfednu frednu efrdnu ferdnu redfnu erdfnu rdefnu drefnu edrfnu derfnu rfdenu frdenu rdfenu drfenu fdrenu dfrenu efdrnu fedrnu edfrnu defrnu fdernu dfernu rendfu erndfu rnedfu nredfu enrdfu nerdfu rednfu erdnfu rdenfu drenfu edrnfu dernfu rndefu nrdefu rdnefu drnefu ndrefu dnrefu endrfu nedrfu ednrfu denrfu nderfu dnerfu rfndeu frndeu rnfdeu nrfdeu fnrdeu nfrdeu rfdneu frdneu rdfneu drfneu fdrneu dfrneu rndfeu nrdfeu rdnfeu drnfeu ndrfeu dnrfeu fndreu nfdreu fdnreu dfnreu ndfreu dnfreu efndru fendru enfdru nefdru fnedru nfedru efdnru fednru edfnru defnru fdenru dfenru endfru nedfru ednfru denfru ndefru dnefru fnderu nfderu fdneru dfneru ndferu dnferu reundf erundf ruendf urendf eurndf uerndf renudf ernudf rneudf nreudf enrudf nerudf runedf urnedf rnuedf nruedf unredf nuredf eunrdf uenrdf enurdf neurdf unerdf nuerdf reudnf erudnf ruednf urednf eurdnf uerdnf redunf erdunf rdeunf dreunf edrunf derunf rudenf urdenf rduenf druenf udrenf durenf eudrnf uedrnf edurnf deurnf udernf duernf renduf ernduf rneduf nreduf enrduf nerduf rednuf erdnuf rdenuf drenuf edrnuf dernuf rndeuf nrdeuf rdneuf drneuf ndreuf dnreuf endruf nedruf ednruf denruf nderuf dneruf rundef urndef rnudef nrudef unrdef nurdef rudnef urdnef rdunef drunef udrnef durnef rnduef nrduef rdnuef drnuef ndruef dnruef undref nudref udnref dunref nduref dnuref eundrf uendrf enudrf neudrf unedrf nuedrf eudnrf uednrf edunrf deunrf udenrf duenrf endurf nedurf ednurf denurf ndeurf dneurf underf nuderf udnerf dunerf nduerf dnuerf rfunde frunde rufnde urfnde furnde ufrnde rfnude frnude rnfude nrfude fnrude nfrude runfde urnfde rnufde nrufde unrfde nurfde funrde ufnrde fnurde nfurde unfrde nufrde rfudne frudne rufdne urfdne furdne ufrdne rfdune frdune rdfune drfune fdrune dfrune rudfne urdfne rdufne drufne udrfne durfne fudrne ufdrne fdurne dfurne udfrne dufrne rfndue frndue rnfdue nrfdue fnrdue nfrdue rfdnue frdnue rdfnue drfnue fdrnue dfrnue rndfue nrdfue rdnfue drnfue ndrfue dnrfue fndrue nfdrue fdnrue dfnrue ndfrue dnfrue rundfe urndfe rnudfe nrudfe unrdfe nurdfe rudnfe urdnfe rdunfe drunfe udrnfe durnfe rndufe nrdufe rdnufe drnufe ndrufe dnrufe undrfe nudrfe udnrfe dunrfe ndurfe dnurfe fundre ufndre fnudre nfudre unfdre nufdre fudnre ufdnre fdunre dfunre udfnre dufnre fndure nfdure fdnure dfnure ndfure dnfure undfre nudfre udnfre dunfre ndufre dnufre efundr feundr eufndr uefndr fuendr ufendr efnudr fenudr enfudr nefudr fneudr nfeudr eunfdr uenfdr enufdr neufdr unefdr nuefdr funedr ufnedr fnuedr nfuedr unfedr nufedr efudnr feudnr eufdnr uefdnr fuednr ufednr efdunr fedunr edfunr defunr fdeunr dfeunr eudfnr uedfnr edufnr deufnr udefnr duefnr fudenr ufdenr fduenr dfuenr udfenr dufenr efndur fendur enfdur nefdur fnedur nfedur efdnur fednur edfnur defnur fdenur dfenur endfur nedfur ednfur denfur ndefur dnefur fndeur nfdeur fdneur dfneur ndfeur dnfeur eundfr uendfr enudfr neudfr unedfr nuedfr eudnfr uednfr edunfr deunfr udenfr duenfr endufr nedufr ednufr denufr ndeufr dneufr undefr nudefr udnefr dunefr nduefr dnuefr funder ufnder fnuder nfuder unfder nufder fudner ufdner fduner dfuner udfner dufner fnduer nfduer fdnuer dfnuer ndfuer dnfuer undfer nudfer udnfer dunfer ndufer dnufer
Note: these 'words' (valid or invalid) are all the permutations of the word refund. These words are obtained by scrambling the letters in refund.