Adjacent means when two things are side-by-side or next to each other. In a class, every bench has 2 students sitting next to each other is considered as adjacent. ADJACENT definition: lying near, close, or contiguous; adjoining; neighboring. See examples of adjacent used in a sentence. ADJACENT definition: 1. very near, next to, or touching: 2. used in compounds to show that something is not exactly the…. Learn more. If one thing is adjacent to another, the two things are next to each other. He sat in an adjacent room and waited. The schools were adjacent but there were separate doors. adjacent, adjoining, contiguous, juxtaposed mean being in close proximity. adjacent may or may not imply contact but always implies absence of anything of the same kind in between. There are six meanings listed in OED's entry for the word adjacent, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence. Define adjacent. adjacent synonyms, adjacent pronunciation, adjacent translation, English dictionary definition of adjacent. adj. 1. Close to; lying near: adjacent cities. Adjacent means close to or near something. You may consider the people up and down your street to be neighbors, but your next-door neighbor is the person who lives in the house or apartment adjacent to yours. ADJACENT meaning: 1. very near, next to, or touching: 2. used in compounds to show that something is not exactly the…. Learn more. Some common synonyms of adjacent are adjoining, contiguous, and juxtaposed. While all these words mean being in close proximity, adjacent may or may not imply contact but always implies absence of anything of the same kind in between.