The term "dangling line" can be replaced with a variety of synonyms depending on the context. In the context of fishing, the term "dropped line" or "slack line" can be used to refer to a line that isn't being actively pulled or trolled. Alternatively, if the line is hanging or swaying, the terms "flapping line" or "swinging line" could be used. In a more literary or symbolic sense, the term "loose thread" or "tenuous connection" could be used to refer to a line that is barely holding on. Overall, there are many options when it comes to describing a dangling line that can better fit the specific situation at hand.