Understand, underachieve, upset, use.
A letter that starts with U is an urgent letter.
HOP is a verb right? It also starts with letter "H"
letter that starts with u is unicorne
A six letter word that starts with U is upward.
The Ukulele starts with the letter U.
instigate
opened
kick
quit
· improvise
Union Station starts with U.
A tool that starts with U is a utility knife.