Majha
The partition split the Punjab Province (British India) into the two states of West Punjab (Punjab, Pakistan) and East Punjab. However, the historic Majha region is arguably still the same as before since the partition does not change the previous history of Punjab, therefore does not change the geography of the Majha region of the historic Punjab region.
Punjab Muslim League
On 28 January 1933, Choudhary Rahmat Ali voiced his ideas in the pamphlet entitled "Now or Never; Are We to Live or Perish Forever?" The word 'Pakistan' referred to "the five Northern units of India, viz. : Punjab, North-West Frontier Province (Afghan Province), Kashmir, Sind and Baluchistan"". By the end of 1933, the word "Pakistan" became common vocabulary where an “I” was added to ease pronunciation (as in Afghan-i-stan).
In a subsequent book Rehmat Ali discussed the etymology in further detail.
"Pakistan' is both a Persian and an Urdu word. It is composed of letters taken from the names of all our South Asia homelands; that is, Punjab, Afghania, Kashmir, Sindh and Balochistan. It means the land of the Pure".