Ba means
Srimad-Bhagavatam
SB Canto 7
Ba means byarthatā, disappointment.
SB 7.13.25, Purport: Material life is called pavarga because here we are subject to five different states of suffering, represented by the letters pa, pha, ba, bha and ma. Pa means pariśrama, very hard labor. Pha means phena, or foam from the mouth. For example, sometimes we see a horse foaming at the mouth with heavy labor. Ba means byarthatā, disappointment. In spite of so much hard labor, at the end we find disappointment. Bha means bhaya, or fear. In material life, one is always in the blazing fire of fear, since no one knows what will happen next. Finally, ma means mṛtyu, or death. When one attempts to nullify these five different statuses of life—pa, pha, ba, bha and ma—one achieves apavarga, or liberation from the punishment of material existence.