The only free and comprehensive online etymological dictionary of the Spanish language
rojo m. (Adjective, Noun) "red"

15th cent. From Latin russus 'id.' From Proto-Italic *rut-to- 'id.' From an early pre-form *ru̯dh-to- 'id.,' from a root in Proto-Indo-European *h1ru̯dh- "to be red."

Romance: Western Vulgar Latin: Asturian royo, Portuguese roxo, russo, Catalan ros, French roux, Italian rosso ; Eastern Vulgar Latin: Aromanian arosh, Romanian roșu
romper (Verb) "to break"

12th cent. From Latin rumpere 'id.' From Proto-Italic *runp- 'id.' From Proto-Indo-European *h3ru-n-p- 'id.'

Romance: Western Vulgar Latin: Portuguese romper, Catalan rompre, French rompre, Italian rompere ; Eastern Vulgar Latin: Aromanian arup, Romanian rupe
ropa f. (Noun) "clothes"

10th cent. Old Spanish raupa. 11th cent. Old Spanish roppa. Originally meaning "cargo." Borrowed from Gothic *rauba "spoils," but probably also "clothing" (compare Old English reaf, meaning both "loot" and "clothing"). From Proto-Germanic *rauba- "loot" From Proto-Indo-European *Hrou̯p-ó- 'id.' From the root *Hreu̯p- "to plunder," "to break away."

Romance: Western Vulgar Latin: Portuguese roupa, Italian roba

Germanic: West Germanic: Old High German roub "robbery," "spoils," Old Saxon nōd-rōf "violent robbery," Old English rēaf "garment," "booty"

Indo-European: Indo-Iranian: Sanskrit lumpáti "to tear," Old Avestan urūpaiia- "to cause racking pain"
roto (Adjective) "broken"

12th cent. From Latin ruptus 'id.,' from rumpere "to break" (see romper).

Romance: Western Vulgar Latin: Asturian rotu, Portuguese roto, Italian roto ; Eastern Vulgar Latin: Aromanian aruptu, Romanian rupt ; Sardinian: ruttu
rótulo m. (Noun) "label"

Early 18th cent. borrowing from Latin rotulus "little wheel," from rota "wheel" (see rueda) and dimminutive suffix -ulus (see -uelo).
rueda f. (Noun) "wheel"

13th cent. Old Spanish rueda. From Latin rota 'id.' From Proto-Italic *rot-ā- 'id. From Proto-Indo-European *Hrot-o/h2- "wheel," but originally "revolving." From a root *Hret- "to roll."

Part of names in toponyms in Palencia, Guadalajara, Zaragoza, and Valladolid (e.g., Rueda de Medina). Also the origin of Ruedas, a town in Soria, and Ruedes, a town in Oviedo.

Romance: Western Vulgar Latin: Asturian rueda, Portuguese roda, Galician roda, Catalan roda, French roue, Italian ruota ; Eastern Vulgar Latin: Aromanian aroatã, Romanian roată ; Sardinian: roda

Indo-European: Celtic: Gaulish Roto-magus "wheel market," Old Irish roth "wheel," reithid "to flow," Old Welsh redec 'id.,' Old Breton redec 'id.,' Middle Cornish resek 'id.;' Germanic Old High German rad "wheel," Old Dutch rath 'id.,' Old Frisian reth 'id.;' Balto-Slavic: Lithuanian rãtas "wheel," "circle," Latvian rats 'id.;' Indo-Iranian: Sanskrit rátha- "chariot," Young Avestan raθa- 'id.'

"From the reconstructible words it is clear the Proto-Indo-European community were familiar with wheeled vehicles and had the necessary terminology for wheels, axles, shafts, and yokes. It may be significant that the words we can reconstruct for this semantic field are both semantically and morphologically transparent, e.g. *kwekwlo- 'wheel' (róth2os 'wheel' (The Oxford Introduction to Proto-Indo-European and the Proto-Indo-European World (2006)
ruido m. (Noun) "noise"

12th cent. Old Spanish roído. From Latin rugitus 'id.' From rugire "to roar." Probably from an imitative root in Proto-Indo-European *h3ru-.

Romance: Western Vulgar Latin: Portuguese ruído, French rut, Italian ruggito ; Eastern Vulgar Latin: Romanian ruget