This is an overview on the principle of semantic holism, according to which an expression cannot have a meaning in isolation from all other expressions of the same language. In section one I discuss the levels of commitment to semantic holism of the three main conceptions of meaning: (a) the truth-conditional conception; (b) the physicalistic conception; (c) the conceptual role conception. In section two I confront the principle of semantic holism with the principle of compositionality, according to which the meaning of a complex expression is a function of the meaning of its component expressions and of their mode of composition. In section three I discuss the relevance of semantic holism for the notions of understanding and communication. In section four I draw some conclusions on the role semantic holism plays in the attempts to solve the problem of the indeterminacy of meaning. In section five I investigate the contacts between semantic holism and the notion of analyticity.