What does "casbah" mean?

The fortress in a city in North Africa or the Middle East.

What is a synonym for "casbah"?

Common synonyms include: kasbah.

/ˈkaz.bɑː/ noun, slang

noun, slang ·Moderate ·College level

Noun

1
The fortress in a city in North Africa or the Middle East.
2
an older or native quarter of many cities in northern Africa; the quarter in which the citadel is located wordnet
3
The medina, the older part of a city in North Africa or the Middle East.
"The king called up his jet fighters / He said, "You better earn your pay / Drop your bombs between the minarets / Down the casbah way""
4
A person's house or flat/apartment. slang
"He gave me an earth-shattering kiss and whispered, “Come to my casbah and let me ply you with cupcakes.” […] We made good time getting to his apartment."

"The Casbah is part of Algiers's cultural heritage."

Borrowed from Arabic قَصَبَة (qaṣaba).