Transliteration: rang bzhin
<phrase> "Nature". Translation of the Sanskrit "svabhāva". Some of the implications of this term can be understood through a consideration of the formulation that is generally used to understand a given phenomenon: ངོ་བོ་, རང་བཞིན་, and བྱེད་ལས་ "entity, nature, and function". The རང་བཞིན་ nature of something is the nature of some ངོ་བོ་ particular entity, the particular qualities of the entity, and because the entity has those qualities there is some effect, something happens accordingly. E.g., fire is hot and burns, ice is cold and cools: the entity fire is hot by nature because of which it burns; the entity ice is cold in nature cold because of which it cools. In this kind of formulation, nature simply means "the quality" or "the feature" of some entity. E.g., in the Mahāmudrā and in the Thorough Cut path of Great Completion, the essence of mind is described with the threefold formulation of entity, nature, and function. In that situation, the entity is emptiness, the nature or quality of that emptiness is འོད་གསལ་བ་ luminosity and the function of that entity with that nature is one of all-pervasive compassionate activity.In the sense just described རང་བཞིན་གྱིས་ is a freq. used phrase that means "naturally", i.e., something happens as a matter of something having certain qualities. One problem here is that modern American language, with its emphasis on casualness, has give the term "naturally" the meaning of "effortlessly, spontaneously" but that is definitely not the meaning intended here by "naturally". Note that in some terms the connector གྱིས་ is dropped so that རང་བཞིན་ comes to mean "naturally". (Note that sometimes རང་བཞིན་གྱིས་ translates Sanskrit constructions in which case it can have a different meaning e.g., in རང་བཞིན་གྱིས་སྟོང་པ་ it means "of nature".)
The term རང་བཞིན་ "nature" is also used synonymously with the terms གཤིས་ཀ་, the inner disposition / character of something.
The term རང་བཞིན་ "nature" is heavily used in all levels of Buddhist philosophy. Sometimes it is used in the above sense of "basic quality / feature" of some particular thing. However, it is also used, especially when the emptiness of something is being considered, to give the sense of a fixed entity. E.g., the common term of the དབུ་མ་ Madhyamaka level of philosophy རང་བཞིན་གྱིས་གྲུབ་པ་ "inherently existent" literally means "come into existence through having a nature" where a nature means that there is a fixed entity.