Is a “‘Junction’ Table” the same as a Weak Entity?

A junction table is a weak entity, but a weak entity often is not a junction table. A junction table is not the same as a weak entity. A junction table is a type of weak entity.

Tables used to resolve repeating groups are also weak entities. These are only junction tables if the repeating group contains a repeated foreign key relationship.

Depends how you define a "junction table". ER terminology tends to be somewhat ambiguous when used to describe relational database concepts.

A junction table typically means or can mean any table with two or more foreign keys.

A weak entity on the other hand is represented by a table whose primary key includes at least one foreign key attribute. That doesn't have to be the case for a junction table (i.e. a table with more than one foreign key).