The only free and comprehensive online etymological dictionary of the Spanish language
ejemplo m. (Noun) "example"

12th cent. From Latin exemplum 'id.,' from eximere "to select." From ex- "out" (see ex-) and emere "to take" (see asunto).

Romance: Western Vulgar Latin: Portuguese exemplo, Catalan exemple, French exemple, Italian esempio; Eastern Vulgar Latin: Romanian exemplu
ejército m. (Noun) "army"

15th cent. From Latin exercitus "disciplined," "practiced" from exercere "to keep busy," "exercise." From ex- "from" (see ex-) and arcere "to enclose;" "to defend (from)." From Proto-Italic *ark-e-je/o- "to contain." From Proto-Indo-European *h2ork-ei̯e/o- or *h2orḱ-ei̯e/o- 'id.' From *h2erk- "to hold."

Romance: Western Vulgar Latin: Asturian exércitu, Portuguese exército, Catalan exèrcit, esercito; Sardinian: esercito

Italic: Oscan -arak- "building" (in tríbarakavúm "to build")

Indo-European: Hellenic: Ancient Greek ἀρκεῖν (árkeîn) "to defend;" Armenian: argel "hindrance;" Anatolian: Hittite ḫar(k)-zi "to hold"
el (1) m. (Definite Article) "the"

12th cent. From Vulgar Latin ille 'id.,' from Latin ille "that one" (see él).
el (2), él m. (Pronoun) "he," "him"

12th cent. From Vulgar Latin ille 'id.,' from Latin ille "that one." Old Latin ollus. From Proto-Italic *olno- 'id.' From Proto-Indo-European *h2ol-no- "that." From the root *h2el- "that."

Italic: Oscan úlleís "of that," Umbrian ullu "toward that"

Indo-European: Celtic: Gaulish ollo- "beyond," Old Irish ol 'id.,' Middle Welsh ol "according to;" Balto-Slavic: Old Church Slavonic lani "last year," Czech loni 'id.'
elección f. (Noun) "election"

13th cent. From Latin electionem, accusative of electio 'id.' From eligere "to elect" (see elegir).
elegir (Verb) "to choose"

15th cent. A learned form from Latin eligere 'id.,' from ex- "out of" (see ex-) and legere "to choose" (see leer). It replaced the native Old Spanish word esleer.

Romance: Western Vulgar Latin: Portuguese esleger, Catalan elegir, French élire, Italian eleggere
ella f. (Pronoun) "she," "her"

From Vulgar Latin illa 'id.,' from Latin illa "that one." From Proto-Italic *olna 'id.' From Proto-Indo-European *h2ol-na- "that." From the root *h2el- "that." See also la.

Romance: Western Vulgar Latin: Asturian ella, Portuguese ela, Galician ela, Catalan ella, French ella, Italian ella; Eastern Vulgar Latin: Aromanian ea, Romanian ea

Italic: Oscan úlleís "of that," Umbrian ullu "toward that"

Indo-European: Celtic: Gaulish ollo- "beyond," Old Irish ol 'id.,' Middle Welsh ol "according to;" Balto-Slavic: Old Church Slavonic lani "last year," Czech loni 'id.'
ellas f. (Pronoun) (of females) "they," "them"

From Vulgar Latin illas 'id.,' from Latin illas "those."
ello n. (Pronoun) "it"

From Latin illud "that one," from Old Latin ollum. From Proto-Italic *olno- "that." See él.

Italic: Oscan úlleís "of that," Umbrian ullu "toward that"

Indo-European: Celtic: Gaulish ollo- "beyond," Old Irish ol 'id.,' Middle Welsh ol "according to;" Balto-Slavic: Old Church Slavonic lani "last year," Czech loni 'id.'
ellos m. (Pronoun) "them"

From Latin illos 'id.' Plural of ille "that one." See él.