magmentarium — de Vaan
magmentarium 'shrine for the reception of the magmentum' (Varro+). Pit *makio~ 'honoured, blessed', *mak-mn(-to)- 'offering, sacrifice'. PIE *mh2k-(e/o-) 'to make long5. Driessen (px-) proposes a connection with PCI. *make/o- 'to raise, nourish' from 'to make long' (sees s.v. macer). Latin 'honoured' (e.g. made esto 'be honoured') could be understood as. 'made long, made bigger'. This seems slightly more attractive … — [de Vaan, s.v. magmentarium, p. 371]