(also ˈgiven name especially in NAmE ) noun
a name that was given to you when you were born, that comes before your family name :
His first name is Tom and his surname is Green.
Please give all your first names.
( BrE )
to be on first-name terms with sb (= to call them by their first name as a sign of a friendly informal relationship)
( NAmE )
to be on a first-name basis