"Apply to" is a dynamic phrase that is commonly used in different situations. It is often used in a context where an action is being taken concerning something or someone. Synonyms for "apply to" include "relate to," "pertain to," "concern," "be relevant to," "have relevance for," "affect," and "impact." All these words mean the same thing in that they refer to an action that has a direct or indirect relation to someone or something. When using any of these synonyms in place of "apply to," the context of the sentence should be considered to ensure that it fits appropriately.