The only free and comprehensive online etymological dictionary of the Spanish language
mole (3) m. (Noun) "mole sauce"
C. 1861. From Nahuatl molli 'id.'
molestar (Verb) "to bother"
17th cent. From Latin molestare 'id.' From molestus "troublesome" (see molesto).
molesto (Adjective) "troublesome"
15th cent. From Latin molestus 'id.' From Proto-Italic *mōlesto- 'id.' From *melos- "trouble" (see mole (2)).
-mo, -me Relict of an ancient noun-forming derivational suffix.
From Latin -mus (Old Latin -mos) 'id.' From Proto-Italic *-mo-s 'id.' From Proto-Indo-European *-mo-s, a noun-forming suffix denoting an action or the results of that action.
Indo-European
Celtic
Old Irish -macha
Balto-Slavic
Old Church Slavonic -mъ, Russian -m, Polish -m, Old Prussian -mis, Lithuanian -mas
Hellenic
Ancient Greek -μός (-mós)
Indo-Iranian
Sanskrit -má, Avestan -man-
The alternate ending in Spanish, -me, comes from Vulgar Latin *-mis when following an -i- due to i-mutation (e.g., Vulgar Latin *firmis "hold" from Latin firmus 'id.'). From Latin -mus.
momento m. (Noun) "moment"
15th cent. From Latin momentum "moment" also "particle," "movement." From Proto-Italic *mowmn̥to- 'id.,' syncopation of earlier *mowe-mn̥to- (de Vaan 2014). First element *mowe- is from Proto-Italic *mow(a)- "to move" (see mover for continued etymology). Second element *-mn̥to- is a noun-forming suffix (see -miento).
Indo-European
Romance
Asturian momentu, Portuguese momento, Galician momento, Catalan moment, French moment, Italian momento, Romanian moment, Sardinian mamentu
-monio (Suffix) "-ship"
From Latin -monium, indicating an obligation or duty. From monere "to remind" (see muñir).
Indo-European
Hellenic
Ancient Greek -ματ- (mat)
monstruo m. (Noun) "monster"
Early 17th cent. From Late Latin monstruum 'id.,' extended from Latin monstrum 'id.' Derived from monere "to remind," but also "to warn" (see muñir).
Indo-European
Romance
Portuguese monstro, Galician monstro, French monstre, Italian mostro, Romanian monstru
"We see that monstrum must be understood as “a piece of advice,” “a warning” given by the gods. Now the gods express themselves by prodigies, signs which confuse human understanding. A divine “warning” may take the aspect of a supernatural object or being; as Festus says “the term monstra is applied to what goes beyond the natural world, a serpent with feet, a bird with four wings, a man with two heads.” It is only the divine power which can manifest its “warning” in this way. This is why monstrum ceased to have its original meaning. There was nothing in the form of monstrum which suggested anything “monstrous” except the fact that in the doctrine of presages a “monster” represented a divine instruction, a “warning.”" ~ E. Benveniste, Indo-European Language and Society (1973)
monstruo (Noun) monster
Early 17th cent., from earlier 13th cent. Old Spanish mostro. From Latin monstrum "prodigy," "sign," "monster." From Proto-Italic *mone-stro- "sign," from *mon-eje- "to remind" (see muñir).
Indo-European
Romance
Portuguese monstro, Galician monstro, Catalan monstre, French monstre, Italian mostre
Italic
South Picene múfqúlum (?) "monument" (can derive from either *mons-klo- or *mons-tlo-)
monte m. (Noun) "mount"
12th cent. From Latin montem, accusative of mons "mountain." From Proto-Italic *monti- 'id.' From Proto-Indo-European *mon-ti̯- "height."
The origin of the surnames del Monte and de los Montes. Also the origin of Móntez, the name of many towns throughout the Spanish-speaking world.
Indo-European
Romance
Asturian monte, Portuguese monte, Catalan munt, French mont, Italian monte, Aromanian munti, Romanian munte, Sardinian monte
Celtic
Middle Irish moned "mountain," Old Welsh minid 'id.,' Old Breton monid 'id.,' Old Cornish menit 'id.'
Germanic
Old Norse mœnir "ridge of a roof," mœna "to tower"
Indo-Iranian
Avestan maiti- "mountain"
montón m. (Noun) "large amount"
Very early 12th cent. From monte and augmentive suffix -ón.