spanner n.

Proto-Indo-European root meaning "to draw, stretch, spin."

It forms all or part of: append; appendix; avoirdupois; compendium; compensate; compensation; counterpoise; depend; dispense; equipoise; expend; expense; expensive; hydroponics; impend; painter (n.2) "rope or chain that holds an anchor to a ship's side;" pansy; penchant; pend; pendant; pendentive; pending; pendular; pendulous; pendulum; pension; pensive; penthouse; perpendicular; peso; poise; ponder; ponderous; pound (n.1) "measure of weight;" prepend; prepense; preponderate; propensity; recompense; span (n.1) "distance between two objects;" span (n.2) "two animals driven together;" spangle; spanner; spend; spider; spin; spindle; spinner; spinster; stipend; suspend; suspension.

It is the hypothetical source of/evidence for its existence is provided by: Latin pendere "to hang, to cause to hang," pondus "weight" (perhaps the notion is the weight of a thing measured by how much it stretches a cord), pensare "to weigh, consider;" Greek ponos "toil," ponein "to toil;" Lithuanian spendžiu, spęsti "lay a snare;" Old Church Slavonic peti "stretch, strain," pato "fetter," pina "I span;" Old English spinnan "to spin," spannan "to join, fasten; stretch, span;" Armenian henum "I weave;" Greek patos "garment," literally "that which is spun;" Lithuanian pinu "I plait, braid," spandau "I spin;" Middle Welsh cy-ffiniden "spider;" Old English spinnan "draw out and twist fibers into thread," spiðra "spider," literally "spinner."

Old English spinnan (transitive) "draw out and twist fibers into thread," strong verb (past tense spann, past participle spunnen), from Proto-Germanic *spenwan (source also of Old Norse and Old Frisian spinna, Danish spinde, Dutch spinnen, Old High German spinnan, German spinnen, Gothic spinnan), from PIE *spen-wo-, suffixed form of root *(s)pen- "to draw, stretch, spin."

Intransitive senses of "to form threads from fibrous stuff; to twist, writhe" developed in late Old English. Transitive sense of "cause to turn rapidly" is from 1610s; intransitive meaning "revolve, turn around rapidly" first recorded 1660s. Meaning "attempt to influence reporters' minds after an event has taken place but before they have written about it" seems to have risen to popularity in the 1984 U.S. presidential campaign; as in spin doctor, first attested 1984.