There are all sorts of musical terms that mean "loudly" or "Powerfully", including loudly and powerfully!
The habit of using only Italian terms in music has largely passed, not least of causes being the German composers using German terms, the French using French terms, and English and American composers finally starting to use English terms.
For traditionalists, though, the Italian word that most nearly matches loudly or powerfully is "Forte".
Ritardando is a musical term meaning to gradually slow down in tempo.
The musical term for a singing voice that vibrates is vibrato. It is produced by rapidly changing the pitch just slightly.
The musical term for "Soft and Sweet" is Dolce.
Dal segno al Fine is a musical term meaning Repeat from the sign. Then end at the word Fine. SO repeat from Coda
fermata
A musical direction meaning 'to be performed very loudly'
Fortissimo means to play loudly.
sforzando, like an accent, suddenly playing the note loudly and accented
I think "Forte" is the best term I that has that meaning.
Very slowly.
Quasi is an Italian musical term meaning: As if, resembling
A musical term from the Italian Crescendo meaning increasing. From Latin Crescere also meaning to increase. Adopted as a musical term about 1770
Fortissimo is a musical term that means to play very loudly or with great force. It is indicated in sheet music with the abbreviation "ff".
Crescendo is a musical term, meaning to get louder.
Lento or Ritardando
Musical notation usually (but not always) uses Italian. quite = molto (meaning very) quiet = tranquillo (meaning peaceful), tacet (meaning silent)
The Latin term meaning half note is minim.