namesake

Short definition from Wiktionary

Noun

1. 1
   An entity that lends its name to another entity.
2. 2
   An entity that lends its name to another entity: A person with the same name as another.
3. 3
   A person with the same name as another: One who is named after another, often a child named after the parent or an ancestor.
4. 4
   A person with the same name as another: One for whom another is named, often the parent or ancestor who gave the name to a child.
5. 5
   Something (especially a ship, a building, or a medical condition, symptom, or sign) that is named after someone or something.

Verb

1. 1
   To name (somebody) after somebody else.