Explanation:

- Horology: The study and measurement of time. It does not relate to speeches or their nature.

- Harangue: ?? Correct Answer. A long, intense, and possibly boring speech or lecture, often delivered in a critical manner.

- Valediction: A farewell speech, typically delivered at graduations or departure events. It is not inherently long or boring.

- Filibuster: A prolonged speech given to delay proceedings, especially in a legislative setting. It is long and can be boring but is done with the intent to obstruct rather than just being boring.