An account of coherence is proposed which tries to clarify the relationship between semantic relations, metonymy, and the resolution of lexical ambiguity.Coherence is the synergism of knowledge (synergism is the interaction of two or more discrete agencies to achieve an effect of which none is individually capable) and plays a substantial role in cognition. In the account of coherence, semantic relations and metonymy are instances of coherence and coherence is used for lexical ambiguity resolution.This account of coherence, semantic relations, metonymy and lexical ambiguity resolution is embodied in Collative Semantics, which is a domain-independent semantics for natural language processing. A natural language program called metaSuses CS; an example of how it discriminates a metaphorical relation is given