There are thousands of letters that start with U. As a good general rule, to think of a large number of 'U' words, thinks of words that start with 'UN' such as 'Unarmed', 'Unaided', or 'Unruly'. There are other common prefixes such as 'UP' ('Upcast', 'upbeat' etc).
Thinking of these as starting points, you'll think of hundreds.
Ugh, ump, urn and use are 3 letter scrabble words. They begin with the letter u.
Unemployment and urbanization are social study words. They begin with the letter u.
Some Scrabble words that start with U are:upususeunderuncleurineuntoundounclearunnecessaryumbrellaurgentuglyusefulumberutilityunusualunguentuniversalupperundulyundecidedutmostunitunmanageable
Ultimatum, uncle, undertaker and unicorn begin with the letter u. Union, utopia, usual and usage begin with the letter u.
unique
no!
up, us
Unscrew and undertow begin with the letter u. They end with letter w.
Uncertainty, undertow and ulcer are scary. They begin with the letter u.
Ugly
uniformeunionuniqueusineutiliser
uranus