The only free and comprehensive online etymological dictionary of the Spanish language
hora f. (Noun) "hour;" "time"
12th cent. From Latin hora 'id.,' borrowed from Greek ὥρα (hóra) "time," "season." From Proto-Indo-European *Hi̯eh1-r- 'id.' From a root *Hi̯eh1- argued by Beekes (2014) to mean "to send."
Indo-European
Romance
Asturian hora, Portuguese hora, Galician hora, Catalan hora, French heure, Italian ora, Aromanian oarã, Romanian oară, Sardinian òra
Italic
Latin hornus "grown in the year"
Germanic
Gothic jer "year," Old Norse ár, Old High German jār 'id.,' Old Saxon jār, English year
Balto-Slavic
Old Church Slavonic jěrъ "spring," Old Russian jarę "lamb," Lithuanian ė́ras 'id.,' Latvian jẽ̦rs 'id.'
Indo-Iranian
Avestan yārə "year"
horrible (Adjective) "horrible"
15th cent. From horror and -ible, an adjective-forming suffix.
horror m. (Noun) "horror"
16th cent. From Latin horror 'id.,' from the verb horrere "to shudder," "to stiffen." From Proto-Italic *χors-ē- "to surprise." From Proto-Indo-European *ǵhr̥s-eh1- 'id.'
Indo-European
Romance
Portuguese horror, French horreur
Indo-Iranian
Sanskrit hr̥ṣyati "to be delighted," Young Avestan zarəšiiamna- "excited"
hospital m. (Noun) "hospital"
12th cent. From Medieval Latin hospitale "guest lodging," from Latin hospes "guest." From Proto-Italic *χostipot- 'id.,' but more literally "guest master." From *χostis "foreigner," "guest" (see hueste) and *pot- "master" (see poder (2)).
Indo-European
Italic
Paelignian hospus "stranger"
Balto-Slavic
Old Church Slavonic gospodь "god," Russian gospód' "god"
"The primitive notion conveyed by hostis is that of equality by compensation: a hostis is one who repays my gift with a counter-gift. Thus, like its Gothic counterpart, gasts, Latin hostis at one period denoted the guest. The classical meaning “enemy” must have developed when reciprocal relations between clans were succeeded by the exclusive relations of civitas to civitas (cf. Gr. xénos ‘guest’ > ‘stranger’).

"Because of this Latin coined a new name for “guest”: *hosti-pet-, which may perhaps be interpreted as arising from an abstract noun hosti “hospitality” and consequently meaning “he who predominantly personifies hospitality, the one who is hospitality itself.”" ~ E. Benveniste, Indo-European Language and Society (1973)
hotel m. (Noun) "hotel," "hostal"
C. 1855. From French hôtel 'id.,' from Old French hostel, from Medieval Latin hospitale (see hospital).
hoy (Adverb) "today"
12th cent. From Latin hoc die "this day." Hoc comes from hic (see ahí); die from dies (see día).
huello (Noun) (m.) "track;" (f.) "footprint," "fingerprint"
Late 15th cent. Derived from hollar.
hueste f. (Noun) "army;" (pl.) "followers"
12th cent. From Late Latin hostes "army," accusative plural of hostis "enemy." In Vulgar Latin meaning "enemy army." From Proto-Italic *χosti- "foreigner," "enemy." From Proto-Indo-European *ghosti- "stranger," "guest."
Also the origin of the surname de las Huestes.
Indo-European
Germanic
Gothic gasts "guest," Old Norse gestr 'id.' Old High German gast 'id.,' Old English giest (English guest)
Balto-Slavic
Old Church Slavonic gostь "guest," Russian gost' 'id.,' BCS gȏst 'id.,' Polish gość 'id.'
huevo m. (Noun) "egg"
13th cent. From Latin ovum 'id.' From Proto-Italic *ōwo- 'id.' From Proto-Indo-European *h2ōu̯-i̯- 'id.' An ablaut derivation from *h2eu̯-i̯- "bird" (see ave).
Indo-European
Romance
Asturian güevu, Portuguese ovo, Galician ovo, Catalan ou, French œuf, Italian uovo, Aromanian ou, Romanian ou, Sardinian obu
Celtic
Old Welsh ui "egg," Middle Breton uy 'id.,' Old Cornish uy 'id.'
Germanic
Crimean Gothic ada "egg," Old Norse egg 'id.,' Old High German ei 'id.,' Old Saxon ei, Old English ǣg 'id.' (English egg)
Albanian
Albanian ve "egg"
Balto-Slavic
Old Church Slavonic ajce "egg," Russian jajcó 'id.'
Hellenic
Ancient Greek ᾠόν (oión) "egg"
Armenian
Armenian jow "egg"
Indo-Iranian
Avestan aēm "egg"
humano (Adjective, Noun) "human"
12th cent. From Latin humanus 'id.,' from homo "man." From Proto-Italic *χem-ō 'id.' From Proto-Indo-European *dhǵh(e)m-ōn "human," but literally "person from the earth." From *dhh-m- "earth" (see humus (1)).
Indo-European
Romance
Portuguese humano, Catalan humà, French humain, Italian umano, Romanian uman
Celtic
Old Irish duine "man," Welsh dyn 'id.,' Breton den 'id.,' Cornish den 'id.'
Germanic
Gothic guma "man," Old Norse gumi 'id.,' Old High German gomo 'id.,' Old Saxon gumo Old English guma 'id.' (English (matrimony) groom
Balto-Slavic
Old Prussian smunents "man," Lithuanian žmogùs 'id.'
The late Proto-Indo-European word for human, *dhǵh(e)m-ōn, was isolated to the North-West branch (Italic, Celtic, Germanic, and Baltic). It was an innovation on the word for "earth" and not reflective of the oldest layer of the Proto-Indo-European language.