In a bank application form, the maiden name refers to the last name that a person or any of their family members used earlier. It is a crucial field for women who change their last name after marriage, as it is their family name before they got married. In India, women tend to change their last name after marriage, so it is essential to enter their maiden name for identity check reasons. This is because, on the birth certificate, school and college certificates, etc., the maiden name is stated, not the name they choose after marriage. It is also crucial for identity checks and sometimes recovering bank details if something is forgotten.

To summarize, the maiden name is a field in the bank application form that refers to a persons last name or their family members last name before marriage. It is essential for identity checks and is especially crucial for women who change their last name after marriage.