rear
rooster
retailer
renter
roar
rocker
rotor
ratter
rater
rifler
ruler
racer
Some such words are
brier briar biter borer boner bower boxer baser barer buyer
bluer
There are lots of words. Bucolic and bulemic are two examples. I am sure you can find more.
bear
barrier
banker
Brawler
BJ
Some nouns that start with B and end with H are:bathbeachbenchbirchbirthbranchbreathbrunchbrushbush
Birth
abolishaccomplishadmonishafterbirthamateurishaftermathanguishapproacharchashastonishattachautographazimuth
Bosnia and Herzegovina?
huh?
Harmonica
Cash is a 4 letter word that starts with c and ends with h.
abolishaccomplishadmonishafterbirthamateurishaftermathanguishapproacharchashastonishattachautographazimuth
Herpes
zenith
teethtelegraphthightollboothtoothtoothbrushtorchtrashtrenchtruthtwitch
kush