Down-trending is often used to describe a decline or decrease in a particular trend. However, it's important to note that there are several synonyms that can be used to convey the same meaning. One common synonym is "declining", which refers to a decrease or reduction in the trend. Another synonym is "slumping", which suggests a sudden drop in the trend. Other related terms include "faltering", "weakening", "dipping", and "sinking". Each of these synonyms can be used interchangeably with down-trending to convey a similar message. It's important to choose the right word that accurately reflects the nature of the trend you are discussing.