umbre mubre ubmre bumre mbure bmure umrbe murbe urmbe rumbe mrube rmube ubrme burme urbme rubme brume rbume mbrue bmrue mrbue rmbue brmue rbmue umber muber ubmer bumer mbuer bmuer umebr muebr uembr eumbr meubr emubr ubemr buemr uebmr eubmr beumr ebumr mbeur bmeur mebur embur bemur ebmur umreb mureb urmeb rumeb mrueb rmueb umerb muerb uemrb eumrb meurb emurb uremb ruemb uermb eurmb reumb erumb mreub rmeub merub emrub remub ermub ubrem burem urbem rubem bruem rbuem uberm buerm uebrm eubrm beurm eburm urebm ruebm uerbm eurbm reubm erubm breum rbeum berum ebrum rebum erbum mbreu bmreu mrbeu rmbeu brmeu rbmeu mberu bmeru mebru embru bemru ebmru mrebu rmebu merbu emrbu rembu ermbu bremu rbemu bermu ebrmu rebmu erbmu
Note: these 'words' (valid or invalid) are all the permutations of the word umbre. These words are obtained by scrambling the letters in umbre.