The term "crewcut" refers to a hairstyle that's closely cropped or shaved on the sides and back but slightly longer on top. There are several synonyms for this type of haircut, all of which indicate a similar style. One popular option is the "buzz cut," which involves using clippers to give the hair a uniform length all over. Another synonym is the "butch cut," which refers to a style that's a little bit longer on top than the crewcut. The "high and tight" is another synonym that's popular with military personnel, which is similar to the crewcut but with even shorter sides and back. Overall, these synonyms all describe a short, practical, and low-maintenance hairstyle.