The only free and comprehensive online etymological dictionary of the Spanish language
-ecer Inchoative verb-forming suffix

From Latin -escere, -iscere, and -ascere 'id.,' depending on the vowel stem. From Proto-Italic *-sk-e/o- 'id.' From Proto-Indo-European *-sḱ-e/o- 'id.'

Romance: Western Vulgar Latin: Asturian -ecer, Portuguese -ecer, -escer, Catalan -eix, French -is, Italian -isco; Eastern Vulgar Latin: Aromanian -esc

Italic: Umbrian -sk-

Indo-European: Celtic: Old Irish -c; Balto-Slavic: Lithuanian *-šý- (< prašýti), Old Church Slavonic *-si- (< prositi); Germanic: Gothic *-h- (< fraihnen); Armenian: *-c'a-; Indo-Iranian: Sanskrit *-ch- (> pr̥chā́mi "to ask"), Avestan *-sa (> pərəsa "to ask"); Anatolian: Hittite *-iski indicating repeated action

"The productive descendants of [Proto-Indo-European *-sḱ-é/ó-] differ in meaning from branch to branch. In Anatolian, the suffix indicates repeated, habitual, or background action, or action applied to more than one object... The habitual or durative sense is also found in Homeric Greek... Other Latin verbs with the suffix, however, are inchoatives (indicating the beginning or inception of an action or state)... Several verbs having the suffix that are reconstructible for PIE refer to asking or wishing, indicating perhaps that the suffix also once had a desiderative function." ~ B. Fortson, Indo-European Language and Culture (2011)
echar (Verb) "to throw"

12th cent. From Vulgar Latin *iectare 'id.' From Latin iactare "to hurl," from iacere "to throw" and frequentive suffix -tare (see note under faltar). From Proto-Italic *jak-i- 'id.' From late Proto-Indo-European word *(H)i̯h1-k-i̯- 'id.,' a formation from an originally aorist verb *Hi̯h1- 'id.'

Romance: Western Vulgar Latin: Asturian echar, French jeter, Italian gettare; Sardinian: ghetare

Indo-European: Hellenic: Ancient Greek ἵημι (híemi) "to release," Mycenaean i-je-si 'id.'
-eco Suffix indicating deformity and perversion.

From Nahuatl -ic 'id.' Highly endemic to Central America dialects located in Nahuatl's historic linguistic territory. Not related to the diminutive suffix -eco, from Latin -icus, a variant of -ico.
edad f. (Noun) "age"

12th cent. From Latin ætas 'id.' From Old Latin aivom "time" (see evo) with noun-forming suffix -tas (see -dad).

Romance: Western Vulgar Latin: Asturian edá, Portuguese idade, Galician idade, Catalan edat, Italian età; Eastern Vulgar Latin: Romanian etate
-edad, -idad Noun-forming suffix indicating a state of being.

From Latin -itatem, accusative of -itas 'id.' From Proto-Italic *-i-tāts, an i-stem with suffix *-tāts (see -dad).
edificar (Verb) "to build"

13th cent. From Latin ædificare 'id.' from ædes "building" and facere "to make" (see hacer). Latin ædes is from Proto-Italic *aiþ- "hearth." From Proto-Indo-European *h2i̯dh- "to burn."

Romance: Western Vulgar Latin: Portuguese edificar, French édifier, Italian edificare

Italic: Oscan aídíl, Faliscan efiles, Volscan aidiles

Indo-European: Celtic: Old Irish áed "fire," Welsh aidd "ardor," Middle Breton oaz "jealousy;" Germanic: Old High German eit "pyre," Old English ād 'id.;' Hellenic: Ancient Greek αἴθειν (aíthein) "to burn;" Indo-Iranian: Sanskrit édha- "firewood," -idh- "igniting"
edificio m. (Noun) "building"

13th cent. From Latin ædificium 'id.,' from ædificare "to build" (see edificar).

Romance: Western Vulgar Latin: Portuguese edifício, Catalan edifici, French édifice, Italian edificio; Eastern Vulgar Latin: Romanian edificiu
eeuu m. (Noun) "United States"

An abbreviation of estados unidos. The double letters indicate each respective word is plural. See estado and unir.
efecto m. (Noun) "effect"

15th cent. From Latin effectus "accomplishment," from efficere "to accomplish." From ex- "out of" (see ex-) and facere "to make" (see hacer).

Romance: Western Vulgar Latin: Portuguese efeito, Catalan efecte, French effet, Italian effetto; Eastern Vulgar Latin: Romanian efect; Sardinian: efétu
eh (Interjection) "hey!"

C. 1732. As similar sounding interjections exist in all word languages, an etymology would be difficult nigh impossible.