No, Egyptian is an adjective used to describe something of or from Egypt (a proper noun). Although Egyptian is an adjective, it is still capitalized.
Egyptian is the proper adjective for Egypt.
The word Egyptian is a proper noun as a word for a person of or from the country of Egypt. The word Egyptian is also a proper adjective that describes a noun as of or from the country of Egypt.
The proper adjective for Portuguese is "Portuguese."
The proper adjective for Haiti is Haitian.
The proper adjective for southwest is "southwestern."
Vietnamese is the proper adjective for Vietnam.
The proper adjective for George is Georgian.
The proper adjective for Siam is Siamese.
Freudian is the proper adjective for Freud.
The proper adjective for Georgia is Georgian.
The proper adjective for Mayan is "Mayan."