Dilate (verb)

1. To make something wider or larger, especially by expanding or distending.
2. To cause the pupils of the eyes to widen.
3. To speak at length, to elaborate on a topic.

Origin:

From the latin word dilatare, meaning "to make larger, to widen".

Examples:

1. The balloon was dilated as the air was pumped into it.
2. The doctor dilated the patient's pupils to examine the eyes.
3. The speaker dilated on the topic for over an hour.
4. The blood vessels in the brain dilated in response to the increased blood flow.
5. The student was asked to dilate on the topic in order to show a deeper understanding.