surname
US /ˈsɝː.neɪm/
UK /ˈsɝː.neɪm/

1.
a hereditary name common to all members of a family, as distinct from a given name.
:
•
Her surname is Smith.
•
Please write your first name and surname on the form.
a hereditary name common to all members of a family, as distinct from a given name.