Just make sure you add your definition sentence between double quotes (like "your definition here"). I just tested here and it worked just fine.
How to import a quoted csv file into Purview's glossary?
While importing terms into Purview's business glossary, I would like to import a term whose definition is a sentence that includes commas and other characters. But, once the template provided by Purview is in.csv format, I'm having some trouble accomplishing this task. Is there a way you can do this? Maybe through a quoted .csv file?