This is the 618th most frequent Spanish word.
materia
"Materia" in Spanish means "subject" (as in a school subject) or "matter" (as in physical substance).
Here, 'materia' refers to an academic subject or field of study.
La física es una materia fascinante.
Physics is a fascinating subject.
Here, 'materia' is used to mean a topic or matter of discussion.
Ese tema es una materia que debemos discutir más a fondo.
That topic is a matter we must discuss further.
In this sentence, 'materia' represents physical matter or substance.