From The Free On-line Dictionary of Computing (19 January 2023):
entity-relationship diagram
ERD
<data, database, specification> A visual representation of an
entity-relationship model.
An entity-relationship diagram has a box for each entity,
containing its properties, and lines between boxes for
relationships. The ends of the lines are labelled to show the
type of relationship - one-to-one, one-to-many or
many-to-many.
(2019-11-03)