Majles or Majlis is an Arabic/Persian term for "Sitting Room" and can roughly translate into "Council" or more generally "Legislature". It's in fact the name of Iranian parliament both before and after the 1979 Revolution.
The idea is that it can replace "Arab" as an identifier the same way the USSR promoted an All-Union "Soviet" identity. Since while the word Arab has dropped its ethno-nationalist connotations in TLMTL upon the Pan-Arab state becoming the champion of socialist internationalism (for the most part), it hasn't OTL.