Collar/ˈkɑːlər/ Definition 1 of 5Pro Tip 1/3Formal Attire Collars are important in formal dress codes, often signaling professionalism or formality. Ensure your collar is neat for the job interview. Pro Tip 2/3Casual Style Some collars are designed to be worn casually, like polo shirt collars that are softer. He wore a casual shirt with a soft collar. Pro Tip 3/3Fashion Statement 'Popping your collar' can be a fashion statement, especially with jackets or coats. She popped the collar of her leather jacket for style.