psi

See also: Psi, PSI, psí, and pśi

Translingual

Etymology

Abbreviation of English Pashayi.

Symbol

psi

1. (international standards) ISO 639-3 language code for Southeast Pashayi.

See also

• Wiktionary’s coverage of Southeast Pashayi terms

English

Ancient Greek alphabet

← chi		→ omega
Ψ ψ Ancient Greek: ψεῖ
Wikipedia article on psi

Etymology 1

From Middle English psi, from Latin psī, from Ancient Greek ψεῖ (pseî), the name for the twenty-third letter of the alphabet (Ψ, ψ).

Pronunciation

Greek letter

• enPR: psī, sī, IPA^(key): /psaɪ/, /saɪ/

• Audio (US); “psi” (Greek letter):

  (file)

• Homophones: xi, sigh, scye, sai, Si (all for the latter pronunciation only)
• Rhymes: -aɪ

Psychic energy

• enPR: sī, IPA^(key): /saɪ/

• Audio (US):

  (file)

• Homophones: xi, sigh, scye, sai, Si
• Rhymes: -aɪ

Noun

psi (countable and uncountable, plural psis)

1. (countable) The twenty-third letter of Classical and Modern Greek and the twenty-fifth letter of Old and Ancient Greek.
2. (uncountable, parapsychology, science fiction) A form of psychic energy.
   • 1993, Will Self, My Idea of Fun:

     ‘Come, lad,’ he said. ‘We will take tea together and speak of the noumenon, the psi and other more heterogenous phenomena.’

   • 1996, Michael F. Stoeber, Hugo Anthony Meynell, Critical Reflections on the Paranormal (page 60)

     When an event is classified as a psi phenomenon, it is claimed that all known channels for the apparent interaction have been eliminated.

   • 2005, Michael Ashley, Transformations: The History of the Science Fiction Magazine 1950 to 1970, Liverpool: Liverpool University Press, page 133:

     It traces the growth of homo gestalt with the uniting of six lovely outcasts of society who have psi powers and come together as a hive mind, thus creating a gestalt super-being.

Derived terms

• psi function
• psi particle
• psivamp

Translations

Greek letter

• Arabic: پْسِي m (psī), بْسِي m (bsī)
• Asturian: psi (ast)
• Catalan: psi (ca) f
• Chinese:

  Mandarin: 普西 (zh) (pǔxī)

• Czech: psí (cs) n
• Dutch: psi (nl) m or f
• Esperanto: psio (eo)
• Finnish: psii (fi)
• French: psi (fr) m
• German: Psi (de) n
• Greek: ψι (el) n (psi)

  Ancient Greek: ψεῖ n (pseî)

• Hebrew: פְּסִי f (psi)
• Hungarian: pszi (hu)
• Interlingua: psi
• Irish: sí f
• Italian: psi (it)
• Japanese: プシー (ja) (pushī), プスィ (pusi), プサイ (ja) (pusai)
• Korean: 프시 (ko) (peusi)
• Malay: psi
• Persian: سای (fa)
• Polish: psi (pl) n
• Portuguese: psi (pt) m
• Russian: пси (ru) n (psi)
• Spanish: psi (es) f

psychic energy

See also

• (Greek-script letter names) alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega

Etymology 2

Initialism of pounds per square inch.

Alternative forms

• P.S.I., PSI

Symbol

psi

1. Pound per square inch (an imperial unit of pressure)
   • 2017 December 12, National Transportation Safety Board, “1.3.5 Electrical Generation and Distribution System”, in Marine Accident Report: Sinking of US Cargo Vessel SS El Faro, Atlantic Ocean, Northeast of Acklins and Crooked Island, Bahamas, October 1, 2015‎^[1], archived from the original on 15 May 2022, pages 36–37:

     Each turbogenerator consisted of a steam turbine, powered by 900 psi of superheated steam, that was coupled by a set of reduction gears to a General Electric marine alternating-current generator operating at 1,800 rpm. Each generator had a capacity of 2,000 kilowatts of three-phase power at 450 volts and 60 hertz. The main 450-volt switchboard was energized by the two turbogenerators. The emergency switchboard, in the emergency generator room, was fed from the main switchboard through an electrical tie.

   • 2024 March 23, “Yield Strength of Steel: A Comprehensive Guide”, in Unionfab‎^[2], archived from the original on 13 January 2026:

     For M2, this is typically around 3250 MPa (471,000 psi) when tempered at 300°F (149°C).

Related terms

• psia

Anagrams

• IPS, IPs, ISP, Isp, PIs, SIP, SPI, iPS, isp, pis, sip

Catalan

Pronunciation

• IPA^(key): (Northern, Balearic, Central, Valencia, Northwestern) [ˈpsi]

Noun

psi f (plural psis)

1. Psi; the Greek letter Ψ (lowercase ψ)

Czech

Pronunciation

• IPA^(key): [ˈpsɪ]

Noun

psi

1. nominative/vocative plural of pes

Dutch

Etymology

From Ancient Greek ψεῖ (pseî).

Pronunciation

• IPA^(key): /pʃi/

• Audio:

  (file)

Noun

psi m or f (plural psi's, diminutive psi'tje n)

1. psi (letter of the Greek alphabet)

Further reading

• psi on the Dutch Wikipedia.Wikipedia ^nl

French

Pronunciation

• IPA^(key): /psi/

• Audio (France (Lyon)):

  (file)

• Homophones: psy, psys

Noun

psi m (invariable)

1. psi (Greek letter)

Further reading

• “psi”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

Anagrams

• pis, spi

Italian

Pronunciation

• IPA^(key): /ˈpsi/^*
• Rhymes: -i
• Hyphenation: psì

Noun

psi m or f (invariable)

1. psi (Greek letter)

Anagrams

• spi

Polish

Etymology 1

Inherited from Proto-Slavic *pьsьjь. By surface analysis, pies + -i.

Pronunciation

 

• IPA^(key): /ˈpɕi/

• (Lesser Poland):
  • (Podegrodzie) IPA^(key): [ˈpɕi]

• Audio:

  (file)

• Rhymes: -i
• Syllabification: psi

Adjective

psi (not comparable, no derived adverb)

1. (relational) canine, dog

   Synonyms: pieski, (archaic) sobaczy

Declension

Declension of psi (soft)

	singular				plural
	masculine animate	masculine inanimate	feminine	neuter	virile (= masculine personal)	non-virile
nominative/vocative	psi		psia	psie	psi	psie
genitive	psiego		psiej	psiego	psich
dative	psiemu		psiej	psiemu	psim
accusative	psiego	psi	psią	psie	psich	psie
instrumental	psim		psią	psim	psimi
locative	psim		psiej	psim	psich

Derived terms

nouns

• psia pogoda
• psie pieniądze

Related terms

verb

• psocić impf

nouns

• psota
• psotnica
• psotnik

Etymology 2

Learned borrowing from Ancient Greek ψῖ (psî).

Pronunciation

• IPA^(key): /ˈpsi/
• Rhymes: -i
• Syllabification: psi

Noun

psi n (indeclinable)

1. psi (Greek letter Ψ, ψ)

Etymology 3

Onomatopoeic

Pronunciation

• (Masovia):
  • (Near Masovian) IPA^(key): [ˈpɕi]

Interjection

psi

1. (Near Masovian, often repeated) used to call young dogs

   Coordinate term: a cucu

Derived terms

nouns

• psina
• psinka

Further reading

• “psi”, in Wielki słownik języka polskiego‎^[3] (in Polish), Instytut Języka Polskiego PAN
• “psi”, in Polish dictionaries at PWN‎^[4] (in Polish)
• Władysław Matlakowski (1891), “psi”, in “Zbiór wyrazów ludowych dawnej ziemi czerskiej”, in Sprawozdania Komisyi Językowej Akademii Umiejętności‎^[5], volume 4, Krakow: Drukarnia Uniwersytetu Jagiellońskiego, page 372
• Karol Mátyás (1891), “psi”, in “Słowniczek gwary ludu zamieszkującego wschodnio-południową najbliższą okolicę Nowego Sącza”, in Sprawozdania Komisyi Językowej Akademii Umiejętności (in Polish), volume 4, Kraków: Drukarnia Uniwersytetu Jagiellońskiego, page 328

Portuguese

Pronunciation

• (Brazil) IPA^(key): /piˈsi/, /ˈpsi/

• (Portugal) IPA^(key): /ˈpsi/

• Rhymes: -i
• Hyphenation: psi

Etymology 1

Derived from Ancient Greek ψεῖ (pseî).

Noun

psi m (plural psis)

1. (countable) psi (name of the Greek letter Ψ)

Etymology 2

Noun

psi m or f by sense (plural psis)

1. (informal) clipping of psicólogo

References

• "psi", in Dicionário Priberam da Língua Portuguesa [em linha], 2008-2024, https://dicionario.priberam.org/psi.

Further reading

• “psi”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “psi”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Etymology

Etymology tree

Ancient Greek ψεῖ (pseî)

Greek ψι (psi)bor.

Romanian psi

Borrowed from Greek ψι (psi).

Noun

psi m (plural psi)

1. psi

Declension

	singular		plural
	indefinite	definite	indefinite	definite
nominative-accusative	psi	psiul	psi	psii
genitive-dative	psi	psiului	psi	psilor
vocative	psiule		psilor

Slovak

Pronunciation

• IPA^(key): /psi/, [ˈpsi]
• Rhymes: -i

Noun

psi m anim

1. nominative plural of pes

Spanish

Pronunciation

• IPA^(key): /ˈsi/ [ˈsi]
• Rhymes: -i
• Syllabification: psi

Noun

psi f (plural psíes)

1. psi; the Greek letter Ψ, ψ

Further reading

• “psi”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), 24th edition, Royal Spanish Academy [Spanish: Real Academia Española], 30 October 2026