Faris.. is an area (persia) Farisi.. is the language
Sindh.. is an area Sindhi .. is a language
Bangal.. is an area Bangali.. is a language..
and so on....
You are correct.......................in that context
what I mean just like "Punj" "Ab" is a combination of two Farsi words
similarly..............
"Punj" "Abi" is also combination of two Farsi words
Where "Abi" in Farsi is the "Color BLUE"
so Panjabi can also mean.............
Five Blues.................:D