- A stem-winding watch.
- A rousing oration, especially a political one.
Note contradictory senses of â€œrousing speechâ€ (earlier sense) and â€œboring speechâ€ (later sense); use in the latter sense may be proscribed as a corruption, and is a folk etymology.
US, mid-late 19th century, originally referring to then-recent stem-wind watches (invented in 1840s, commercialized initially 1850s by Patek Philippe & Co.). These were expensive, top-notch watches, hence generalized (1892 ) to â€œtop-notchâ€, particularly applied to speeches, or to the orator in question. Non-speech senses later fell out of use. Nuance of â€œrousingâ€ speech possibly by analogy with watch being wound up (â€œtighten by winding, excite, rouseâ€).
Circa 2000, later sense of â€œinterminable speechâ€ a folk etymology, in sense â€œa speech that lasts so long one must wind oneâ€™s watchâ€.