In NavehSusiya 77, מנחמת may well be simply a PN. More likely, as deduced from the Zoar texts, simply a term for a deceased person rather than the very forced interpretation of "advocate": See now Stern, JSS 63(2017):167f. Indeed it might be better interpreted as a passive rather than active form.
Page refs. in other dictionaries:
DJPA: 317bDNWSI: 725