Formal:
* Monologue: This is the most common and neutral term. It refers to a long speech, typically delivered by a single actor in a play.
* Oration: This implies a formal and often eloquent speech, usually delivered on a special occasion.
* Harangue: This word suggests a forceful and often angry speech, typically delivered to persuade or criticize.
* Dissertation: This term is used for a long, formal, and written speech, often delivered as part of an academic presentation.
* Lecture: This word implies a formal, educational speech, typically delivered to a group of students.
Informal:
* Rant: This implies a long, passionate, and often angry speech, typically delivered without much thought or control.
* Tirade: Similar to rant, but emphasizes the bitter and often abusive nature of the speech.
* Diatribe: This word suggests a bitter, prolonged, and often abusive attack, typically delivered verbally.
* Sermon: This term is used for a long, religious speech, typically delivered by a priest or minister.
The best word to use will depend on the specific context and the tone of the speech.