Legit is a synonym for clean.
graceful
Sanitary.
Some positive words that begin with the letter P:perfectphilanthropicpoisedpowerfulpragmaticpreciousprettyproductiveprofessional
The Hebrew language uses a different alphabet, and there is no "A" in it. But if you mean Hebrew words that transliterate into words beginning with A, there are thousands, including:abbaAdonaiafikomanaggadaahavaakavalamaranaAraviasafataravayalaz
Words that mean the same as the word 'beginning' are: start, origin, outset, onset, inception, source...
Words beginning with you are limited to forms of you, youth and young. If you mean "Happy words beginning with a U sound," perhaps you refer to euphoric.
There are not many words to fit your request, but one comes to mind: quixotic (extravalently romantic).
From the beginning.
dirty
Incompetent and ignorant are mean words. They begin with the letter i.
start from the beginning
positive words beggining with n
Some words are sanitation and sanitize but they mean the exact same thing.
spotless,hygienic