A "loose union" refers to a situation in which a group of entities or individuals are linked together in some way, but their ties are not especially tight or binding. Some possible synonyms for this phrase might include "loose confederation," "loosely affiliated network," "loose association," "loose coalition," or "loose alliance." Other possibilities might include phrases like "tenuous connection," "casual partnership," or "relaxed collaboration." All of these terms imply a certain level of flexibility and informality in the relationship between the parties involved. They suggest that while there may be some common goals or interests driving the group, there is also room for individual variation and autonomy.