__________ is a specific domain in the relation which has entries of all tuples.

The term you're referring to is "Attribute". In the context of a relation in a database, an attribute is a specific domain that contains entries for all tuples. Here's a step-by-step explanation:

1. In a database, data is organized into tables, which are also known as "relations".

2. Each relation is made up of "tuples", which are essentially rows of data.

3. Each tuple consists of one or more "attributes", which are the individual pieces of data that make up the tuple.

4. Therefore, an attribute is a specific domain in the relation that has entries for all tuples. For example, in a relation representing a list of students, the "Name" attribute would contain the name of every student (i.e., every tuple in the relation).