The term "street gutter" can be replaced by several synonyms depending on the context in which it is used. It is commonly referred to as a "curb drain" or "curb inlet" in civil engineering or construction fields. Other synonyms include "channel drain" or simply "channel." In a more casual context, it can also be called a "gutter," "runoff," or "storm drain." The word "gully" can refer to a larger, deeper type of street gutter. It's important to note that some of these synonyms may have specific technical definitions in certain fields, so it's important to use them correctly and in the right context.