There are 990 possible words that can be made, including:
adducer
adhered
adjured
bearded
breaded
daunder
deaired
debeard
defraud
degrade
deluder
denuder
A seven letter word starting with R and ending with O is risotto.
repaper
stencil
seesaw
prairie
Sites
canula
Treat
bellwort
boot
odor
There are no English Scrabble words that meet the criteria. The only word you can make that end with those letters is blank. Here are words you can make with those letters at the beginning of a 7-letter word. blanked, blanker, blanket, blankly