Saguaro
Respite
Tycoon
snowday
scientific Method
Breeder is a 7 letter words using only those letters
Hipster
Respite.
fetuses
Saguaro
There are three 7-letter words possible:roosterrooterstoreros
Core.
There is no 8-letter word that can be made, there are these 7 and 6-letter words though:senegasagenesagonesgenoasgnosesgossanseasonsegnossenega
"EAU" is the only all-vowel three letter word.
hipster
estuary
pluvial