A celluloid collar is a term used to describe a detachable collar made from celluloid material. This type of collar was commonly used in the early 1900s and has become outdated today. However, there are several different synonyms used to describe celluloid collars in modern-day language. Some common synonyms include "dickie collar", "detachable collar", and "neckwear". Other phrases that may be used in lieu of "celluloid collar" include "collar insert", "shirt bib", and "faux collar". Regardless of the terminology used, most people today are unlikely to use or encounter a celluloid collar due to the changes in fashion and clothing technology.