"excellent thing" (especially a rousing speech), 1892, from stem-winding watches (1875), which were advanced and desirable when introduced. See stem (n.) + wind (v.1).
Entries linking to stem-winder
stem n.
Old English stemn, stefn "stem of a plant, trunk of a tree," also "either end-post of a ship," from Proto-Germanic *stamniz (source also of Old Saxon stamm, Old Norse stafn "stem of a ship;" Danish stamme, Swedish stam "trunk of a tree;" Old High German stam, German Stamm), from suffixed form of PIE root *sta- "to stand, make or be firm."
Meaning "support of a wineglass" is from 1835. Meaning "unchanging part of a word" is from 1830. Stems slang for "legs" is from 1860. The nautical sense is preserved in the phrase stem to stern "along the full length" (of a ship), attested from 1620s. Stem cell attested by 1885.
wind v.1
"move by turning and twisting," Old English windan "to turn, twist, plait, curl, brandish, swing" (class III strong verb; past tense wand, past participle wunden), from Proto-Germanic *windan "to wind" (source also of Old Saxon windan, Old Norse vinda, Old Frisian winda, Dutch winden, Old High German wintan, German winden, Gothic windan "to wind"), from PIE *wendh- "to turn, wind, weave" (source also of Latin viere "twist, plait, weave," vincire "bind;" Lithuanian vyti "twist, wind").
Related to wend, which is its causative form, and to wander. The past tense and past participle merged in Middle English. Meaning "to twine, entwine oneself around" is from 1590s; transitive sense of "turn or twist round and round (on something) is from c. 1300. Meaning "set a watch, clockwork, etc. in operating mode by tightening its spring" is from c. 1600. Wind down "come to a conclusion" is recorded from 1952; wind up "come to a conclusion" is from 1825; earlier in transitive sense "put (affairs) in order in advance of a final settlement" (1780). Winding sheet "shroud of a corpse" is attested from early 15c.