What musical term refers to a sudden, sharp accent on a note?

The term that refers to a sudden, sharp accent on a note is "sforzando." This term indicates that the note should be played with a strong emphasis or accent, which draws immediate attention to it as if it has a sudden burst of sound. Sforzando is typically notated with the abbreviation "sfz" in sheet music, and it signifies that the performer should produce the note with a forceful attack, creating a contrast with the surrounding sounds.

In contrast, "forte" means to play loudly, but it doesn't imply the sharp accent needed for a sudden emphasis on a single note. While "staccato" refers to playing notes in a short and detached manner, it does not convey the notion of a sudden accent. “Piano” indicates playing softly, which is the opposite of what is described in the question. Thus, sforzando is the precise term that captures the concept of a sudden, sharp accent on a note.