The phrase "is intrinsic to" implies an underlying and essential relationship between two entities. Synonyms for this phrase include "is fundamental to," "is essential to," "is integral to," and "is inherent in." These terms all convey a sense of necessity and interdependence, emphasizing the significance of the relationship between the two entities. Other related phrases include "is central to," "is crucial to," and "is indispensable to," which all point to the importance of a particular element to the functioning or existence of something else. Using these synonyms can add depth and nuance to descriptions and explanations, highlighting the essential and indispensable nature of a particular aspect or factor.