Catercorner is an adjective that means diagonal or angled. Some common antonyms for catercorner include straight, perpendicular, parallel, and adjacent. Straight refers to a direct, uninterrupted line. Perpendicular refers to two lines that intersect at a 90-degree angle. Parallel refers to two lines that never intersect and run side by side. Adjacent refers to two things that are next to each other, but not angled or diagonal. Antonyms can be helpful in providing a contrast to the meaning of a word, allowing for better understanding and communication.