Words starting with R and ending with U:
rondeau
A word that starts with A and ends with U: apercu.
A word that starts with U and ends with G: understanding.
A word that starts with E and ends with U: ecru.
uvula
utterer,
guru
undertow
Uranium
One word that starts with U and ends in E is "unique."
univ
A word that starts with y and ends with y is yay .