What term refers to something that is tediously prolonged or tends to speak or write at great length?

The term that refers to something that is tediously prolonged or tends to speak or write at great length is "prolix." This word specifically conveys the idea of excessive verbosity and a tendency to be long-winded, often leading to a lack of clarity or conciseness in communication. A prolix piece of writing or speech includes an abundance of unnecessary details, making it burdensome for the audience to engage with.

While "verbose" also describes a style that contains more words than necessary, it doesn’t carry the same connotation of being tediously long as "prolix" does. "Lengthy" simply indicates something that is long but doesn’t inherently imply tediousness or excessive detail. "Protracted" refers to something that has been drawn out in time, which is related but does not specifically refer to the manner of speaking or writing as "prolix" does. Thus, "prolix" precisely captures the essence of being tediously lengthy in expression.