The only free and comprehensive online etymological dictionary of the Spanish language
motor m. (Adjective, Noun) "motor"
17th cent. From Latin mot- "set in motion" interpreted as an agent noun (e.g., moto "I set in motion," motus "is set in motion"). Deriving from the verb movere "to move" (see mover).
motriz (Adjective) "motor;" "driving"
From motor.
mover (Verb) "to move"
12th cent. From Latin movere 'id.' From Proto-Italic *mow- "to move," an aorist formation from Proto-Indo-European *meu̯h1- 'id.'
Indo-European
Romance
Asturian mover, Portuguese mover, Galician mover, Catalan moure, French mouvoir, Italian muovere, Sardinian moere
Balto-Slavic
Old Church Slavonic myti "to wash," Russian myt' 'id.,' Czech mýti 'id.,' Polish myć 'id.,' Slovene míti 'id.,' Lithuanian máudyti "to bathe," Latvian maût "to submerge"
Indo-Iranian
Sanskrit -mī́vantī- "pushing down," Avestan a-muiiamna- "motionless"
Tocharian
A mew- "to shake," B miw- 'id.'
móvil (Adjective) "mobile"
15th cent. Old Spanish móbil. From Latin mobilis 'id.' From Proto-Italic *mowe-blis- 'id.' From *mowe- "to move" (see mover) and *-blis, an adjective-forming suffix (see -il).
Indo-European
Romance
Portuguese móbil, Catalan moble, French mobile, Italian mobile, Romanian mobil
movimiento m. (Noun) "movement"
From mover and -miento, a noun-forming suffix denoting the action of a verb.
muchacho (Noun) "boy," "girl"
13th cent. Old Spanish mochacho. Frequently occuring in as a surname in the earliest texts. Probably from mocho and -acho in the sense of comparing the young to calves yet to grow their proverbial "horns." Note that in some texts where we find the surname Mochocho, we also find Mocho.
Also the origin of the surname Mochacho.
mucho (Adjective) "much"
10th cent. Old Spanish muito, later muncho, mucho, much. From Latin multus 'id.' From Proto-Italic *molto- 'id.' Perhaps from a late Proto-Indo-European root *mol-to- 'id.' or perhaps of unknown origin.
Indo-European
Romance
Asturian munchu, Portuguese muito, Galician moito, Catalan molt, French moult, Italian molto, Aromanian multu, Romanian mult
muelle (Adjective) "soft"
13th cent. From Latin mollis 'id.' From Proto-Italic *moldu-i- 'id.' An adjective formed from an earlier adjective in Proto-Indo-European *ml̥d-u̯- 'id.' via analogy. From *mel- "to soften," "to weaken."
Indo-European
Romance
Portuguese mole, Galician mol, Catalan moll, French mou, Italian molle, Aromanian moali, Romanian moale, Sardinian modde
Celtic
Old Irish mell "pleasant," Middle Welsh blydd "soft"
Balto-Slavic
Old Church Slavonic mladъ "young," Russian molodój 'id.,' Czech mladý 'id.,' Polish mɫody 'id.,' Slovene mlȃd, Old Prussian maldai "boy"
Indo-Iranian
Sanskrit mr̥du- "soft"
muerte f. (Noun) "death"
10th cent. From Latin mortem, accusative case of mors 'id.' From Proto-Italic *morti- 'id.' From Proto-Indo-European *mr̥-ti- "death," but originally "disappearance." From *mer- "to disappear" (see morir).
Indo-European
Romance
Asturian muerte, Portuguese morte, Galician morte, Catalan mort, French mort, Italian morte, Aromanian moarti, Romanian moarte, Sardinian molte
Balto-Slavic
Old Church Slavonic sъmrьtь "death," Russian smert' 'id.,' Czech smrt 'id.,' Polish śmierć 'id.,' Slovene smr̀t 'id.,' Lithuanian mirtìs 'id.'
muerto (1) (Adjective) "dead"
10th cent. From Latin murtuus 'id.' Past participle of mori "to die" (see morir).