rugae urgae rguae gruae ugrae gurae ruage urage rauge aruge uarge aurge rgaue graue rague argue garue agrue ugare guare uagre augre gaure agure rugea urgea rguea gruea ugrea gurea ruega urega reuga eruga uerga eurga rgeua greua regua ergua gerua egrua ugera guera uegra eugra geura egura ruaeg uraeg raueg arueg uareg aureg rueag ureag reuag eruag uerag eurag raeug areug reaug eraug aerug earug uaerg auerg uearg euarg aeurg eaurg rgaeu graeu rageu argeu gareu agreu rgeau greau regau ergau gerau egrau raegu aregu reagu eragu aergu eargu gaeru ageru gearu egaru aegru eagru ugaer guaer uager auger gauer aguer ugear guear uegar eugar geuar eguar uaegr auegr ueagr euagr aeugr eaugr gaeur ageur geaur egaur aegur eagur
Note: these 'words' (valid or invalid) are all the permutations of the word rugae. These words are obtained by scrambling the letters in rugae.