The word "propinquous" refers to something or someone that is near in space, time or relation. Synonyms for this word include "adjacent," "close," "neighboring," "proximate," "immediate," "bordering," "contiguous," and "adjoining." These words all convey the idea of something or someone being in close proximity or connection to another object or person. Other synonyms could include "nearby," "connected," "related," "affiliated," and "parallel." When writing or speaking, it is important to choose the right synonym that best fits the context of the discussion or description of a situation, object or person.