An Evil spirit named Madan embraced severities and received the assistance of Vak siddhi, as indicated by which anything at all he claimed came with reference to. He mishandled this help by annoying sincere folks. A different etymology suggests that valga indicates "to paralyze" and symbolizes the power of stambhana, https://tantramantraaurvigyaan.com/baglamukhi-mantra-sadhna/