The crossword solution for the term 'ISN'T VERTICAL' is LEANS, which is a five-letter word. Leaning is an action that involves the body being tilted or inclined in a particular direction. It can be used to describe a person's posture or the angle of an object. In this case, the term 'ISN'T VERTICAL' implies that something is not standing straight up and down, but is instead leaning in a certain direction.