Expatiate on
Definition 1 of 2
Pro Tip 1/3Academic Contexts
Use 'expatiate on' in formal writing or discussions, typically in academic or scholarly environments. 
In her thesis, she expatiates on the implications of social media.
Pro Tip 2/3Structured Explanation
'Expatiate on' implies a structured, in-depth explanation, not just a casual mention. 
During the lecture, the professor expatiated on the causes of World War II.
Pro Tip 3/3Avoid Repetition
When you expatiate on a topic, offer new insights instead of repeating known facts. 
The speaker expatiated on the study's findings without being repetitive.