Emphasizing Length:
* 冗长演讲 (róngcháng yǎnjiǎng) (Chinese): Literally translates to "prolix speech".
* 冗长乏味 (róngcháng fáwèi) (Chinese): Meaning "long and tedious".
* 长篇大论 (chángpiān dàlùn) (Chinese): Meaning "long and elaborate discourse".
* 冗长 (róngcháng) (Chinese): This simply means "prolix".
* 冗赘 (róngzhuì) (Chinese): Means "redundant and verbose".
* 冗繁 (róngfán) (Chinese): Meaning "prolix and complicated".
* 啰嗦 (luōsuo) (Chinese): Means "long-winded" or "verbose".
* 滔滔不绝 (tāotāo bùjué) (Chinese): Meaning "speaking incessantly".
* 喋喋不休 (diédié bùxiū) (Chinese): Meaning "talking incessantly".
* 长篇大论 (chángpiān dàlùn) (Japanese): Meaning "long and elaborate discourse".
* 冗長 (jūchō) (Japanese): Meaning "prolix".
* 長話短說 (chánghuà duǎnshuō) (Japanese): Means "make a long story short".
* 饒舌 (ráoshé) (Japanese): Meaning "verbose".
* 長々と (nagaku to) (Japanese): Means "at length".
* Verbose
* Prolix
* Wordy
* Long-winded
* Tedious
* Rambling
* Monotonous
* Drawn-out
Emphasizing Technicality:
* Technical jargon
* Technicalese
* Academic lecture
* Specialized discourse
* Esoteric presentation
* Arcane lecture
* Dry lecture
* Dense presentation
* Abstruse discourse
* Unintelligible
* Incomprehensible
Combining Both:
* Dry and lengthy lecture
* Technical and verbose presentation
* Prolix and technical discourse
* Esoteric and monotonous presentation
The best term will depend on the specific characteristics of the speech and the tone you want to convey. You might also consider using a figurative expression, such as "a torrent of technical jargon" or "a droning lecture that seemed to go on forever".
Ultimately, the goal is to clearly and accurately describe the speech in a way that conveys its negative qualities.