The term 'MORAL NATURE' can be broken down into two words: 'MORAL' and 'NATURE'. The term 'MORAL' is defined as a set of principles that guide an individual's behavior, while 'NATURE' refers to the physical world and its phenomena. The crossword solution for this term is 'ETHOS', which is a Greek term meaning 'CHARACTER' or 'CUSTOM'. ETHOS is used to describe the guiding beliefs or ideals that characterize a community, nation, or ideology. In terms of MORAL NATURE, ETHOS can refer to the shared values and beliefs that shape the MORAL CHARACTER of a society.