The only free and comprehensive online etymological dictionary of the Spanish language
puerco (Adjective, Noun) "dirty;" "hog"
11th cent. From Latin porcus 'id.' From Proto-Italic *pork-o- 'id.' From Proto-Indo-European *pórḱ-o- "pig," but originally "digger."
Also in the feminine meaning "slut."
Indo-European
Romance
Asturian puercu, Portuguese porco, Galician porco, Catalan porc, French porc, Italian porco, Aromanian porcu, Romanian porc, Sardinian porcu
Italic
Umbrian purka "sow"
Celtic
Old Irish orc "pig"
Germanic
Old High German farah "pig," Old English fearh 'id.' (English farrow)
Balto-Slavic
Church Slavic prasę "piglet," Russian porosja 'id.,' Czech prase 'id.,' Polish prosię 'id.,' Slovene prasè 'id.,' Old Prussian prastian 'id.,' Lithuanian par̃šas 'id.'
Armenian
Armenian ors "hunt"
Indo-Iranian
Avestan parəsa- "piglet"
"IE *porko- (Latin porcus) denotes the domestic pig as opposed to the wild animal, *sū- (Lat. sūs); The dialect distribution of *porko- leads to the conclusion that only the European tribes practiced pig-breeding.

However, a careful examination shows 1) that in all languages, and particularly in Latin, where the opposition *sū- : *porko- was maintained, both these terms applied to the domesticated species, *porko- designating the piglet as opposed to the adult *sū-." ~ E. Benveniste, Indo-European Language and Society (1973)
puerro m. (Noun) "leek"
13th cent. From Latin porrum 'id.' From Proto-Italic *porso- 'id.' From Proto-Indo-European *pr̥so- 'id.' Borrowed from a non-Indo-European language. It's difficult to connect the Indo-Iranian meanings of "ear of corn" with the Latin and Greek meanings of "chives." Therefore, despite the phonological congruity, it may be that the Greek and Latin words were borrowed from a non-Indo-European language spoken near or in Europe, and do not stretch back to Proto-Indo-European. See also de Vaan (2015).
Indo-European
Romance
Portuguese porro, Galician porro, Catalan porro, French poireau, Italian porro, Romanian por
Hellenic
Ancient Greek πράσον (práson) "leek"
Indo-Iranian
Sanskrit parṣá- "sheaf," Young Avestan parša- "ear of corn"
puerta f. (Noun) "gate," "door"
12th cent. From Latin porta 'id.' From Proto-Italic *portā- 'id.,' generalized as a noun from an adjective in Proto-Indo-European *pr̥-to- "crossed." See also portar, pro-.
Indo-European
Italic
Oscan púrtam "gate"
Celtic
Gaulish ritu- "ford," Middle Irish -rith 'id.' Old Welsh rit 'id.,' Old Breton rit 'id.,' Cornish rid 'id.'
Germanic
Old Norse fjǫrðr "fjord," Old High German furt 'id.,' Old Saxon ford 'id.,' Old English ford
Indo-Iranian
Avestan pərətu- "crossing"
puerto m. (Noun) "port"
11th cent. From Latin portus "harbor." From Proto-Italic *portu- 'id.' From Proto-Indo-European *pr̥-tu̯- "crossing." From *per- "to cross." See also puerta, portar.
Indo-European
Romance
Asturian puerta, Portuguese porta, Galician porta, Catalan porta, French porte, Italian porta, Aromanian poartã, Romanian poartă, Sardinian polta
Italic
Oscan púrtam "gate"
Celtic
Gaulish ritu- "ford," Middle Irish -rith 'id.' Old Welsh rit 'id.,' Old Breton rit 'id.,' Cornish rid 'id.'
Germanic
Old Norse fjǫrðr "fjord," Old High German furt 'id.,' Old Saxon ford 'id.,' Old English ford
Indo-Iranian
Avestan pərətu- "crossing"
pues (Conjunction, Adverb) "so;" "thus;" "then"
12th cent. Borrowed from Medieval Latin post "after," originally "behind," which replaced the native words po and pu entirely except in the Chilean dialect. From Old Latin poste. From Proto-Italic *pos-ti 'id.' From Proto-Indo-European *pos 'id.'
Indo-European
Romance
Portuguese pois, French puis, Italian poi, Romanian păi
Italic
Oscan púst "after," Umbrian pus 'id.'
Balto-Slavic
Old Church Slavonic pozdě "late," Russian pózdyj 'id.,' Czech pozdě 'id.,' Slovene pozd 'id.,' Lithuanian pàs "on"
Hellenic
Ancient Greek πός (pós) "at"
Indo-Iranian
Sanskrit paścā́ "after," Young Avestan pasca 'id.'
puesto (Adjective) "put," "set"
From the past participle of poner.
Indo-European
Romance
Portuguese posto, Catalan post, French poste, Italian posto
pulsar (Verb) "to push (a button);" "to throb"
16th cent. From Latin pulsare "to push," "to urge," a frequentive from pellere "to push," "to strike." From Proto-Italic *pelna-C- "to approach." From Proto-Indo-European *pl̥-n-h2- 'id.'
Indo-European
Romance
Portuguese puxar, French pousser, Italian pulsare, Romanian pusa
Italic
Umbrian ampentu "he brought near"
Celtic
Old Irish adella "to visit," Middle Welsh el "goes," Middle Breton yal 'id.,' Cornish gallas "went"
Hellenic
Ancient Greek πίλναμαι (pílnamai) "to approach"
Armenian
Armenian elanem "exit"
pulso m. (Noun) "pulse"
13th cent. From Latin pulsus "pulse," but more literally "beat." Replacement of a pre-form *pulto- 'id.' From Proto-Italic *polto- "push," probably earlier "drawn near." From Proto-Indo-European *pl̥h2-to- "approached." From the root *pelh2- "to approach."
Indo-European
Romance
Portuguese pulso, Catalan pols, French pouls, Italian polso, Romanian puls
Italic
Venetic poltos "disturbed"
Hellenic
Ancient Greek πλησιάζω (plisiázo) "I approach"
pungir (Verb) "to prick"
From Latin pungere 'id.' From Proto-Italic *pung- "to pierce." From Proto-Indo-European *pu̯-n-g- 'id.'
Indo-European
Romance
Portuguese pungir, French poindre, Italian pungere, Aromanian pungu, Romanian punge, Sardinian púnghere
Hellenic
Hellenic Ancient Greek πύξ (pydz) "with the fist"
punta f. (Noun) "point;" "apex"
Very early 15th cent. From Medieval Latin puncta "point," earlier "puncture." The word replaced earlier punzada. From pungere "to puncture" (see pungir).