A negative conjunction is a type of conjunction that expresses a negative idea. The most common negative conjunctions are 'NOR, ' 'NEITHER, ' and 'BUT.' The crossword solution for the term 'negative conjunction' is NOR, which is a two-letter word that expresses a negative idea. It is often used in sentences to express a contrast between two ideas or to express a negative idea in a sentence. For example, 'I don't like apples NOR oranges.'