If the word is derived from Farsi language, then it has two parts - be and neshan. 'Neshan' or 'nishan' pronounced as in the car nissan, means blemish or trace or origins and 'be' pronounced like be in word better. means without. So could it be a mango without blemish or without trace or origins. However google says it is named after a 'zamidar' an aristocrat or a land-owner of those days in India.