Viscountess
/ˈvaɪkaʊntəs/
Definition 1 of 1
Pro Tip 1/3Title vs. Person
Distinguish between the nobility title 'viscountess' and the person. It's respectful to use her full title. 
Viscountess Astor, may I have a moment?
Pro Tip 2/3Hereditary Status
Understand that 'viscountess' can indicate a hereditary position within the nobility hierarchy. 
The viscountess inherited her title from her parents.
Pro Tip 3/3Cultural Significance
Recognize that the term 'viscountess' is associated with British and European nobility. 
In British history, the viscountess often held significant social power.