earst aerst erast reast arest raest easrt aesrt esart seart asert saert ersat resat esrat serat rseat sreat arset raset asret saret rsaet sraet earts aerts erats reats arets raets eatrs aetrs etars tears aters taers ertas retas etras teras rteas treas artes rates atres tares rtaes traes eastr aestr esatr seatr asetr saetr eatsr aetsr etasr teasr atesr taesr estar setar etsar tesar stear tsear aster sater atser taser staer tsaer ersta resta esrta serta rseta sreta ertsa retsa etrsa tersa rtesa tresa estra setra etsra tesra stera tsera rstea srtea rtsea trsea strea tsrea arste raste asrte sarte rsate srate artse ratse atrse tarse rtase trase astre satre atsre tasre stare tsare rstae srtae rtsae trsae strae tsrae
Note: these 'words' (valid or invalid) are all the permutations of the word earst. These words are obtained by scrambling the letters in earst.