جَاءَنِي زَيْدٌ الْعَالِمُ — Learned Zayd came to me.
زَيْدٌ: nominative proper-name subject, definite.
الْعَالِمُ: nominative, definite, masculine singular direct adjective.
The definite article on the adjective makes it match the proper noun in definiteness.
Opening interactive controls...
The Tawābiʿ and Naʿt: Direct and Relational Attributes
جَاءَنِي زَيْدٌ الْعَالِمُ — Learned Zayd came to me.
زَيْدٌ: nominative proper-name subject, definite.
الْعَالِمُ: nominative, definite, masculine singular direct adjective.
The definite article on the adjective makes it match the proper noun in definiteness.