sub-

From Latin sub- (“under”). Doublet of hypo-.

• enPR: sŭb, IPA^(key): /sʌb/

• Audio (US):

  (file)

• Audio (General American):

  (file)

sub-

1. Under, beneath.

   subterranean

   submarine

   • 2020 March 14, Lindsay del Valle, “36 Spanish Prefixes That Will Increase Your Vocabulary Times 100!”, in Homeschool Spanish Academy‎^[1]:

     Contrarily, the prefix “sub-” doesn’t change meaning so much as it provides specificity, as seen in the difference between “title” and “subtitle.”

2. Subsidiary, secondary.

   subplot

3. Almost, nearly.

   subconical

   subequatorial

In Latin, the following sound changes affected "sub-" and cause English borrowings from Latin which contain this prefix to have different forms. Words formed in English using the prefix "sub-" do not exhibit these sound changes. (Combination with 's' involved elision and the other changes involved assimilation.)

• sub + c = suc- (hence succession, from Latin successiō; but e.g. subculture formed in English from sub- + culture)
• sub + p = sup- (support, but subpage)
• sub + c, p or t = sus- (susceptible, suspend, sustain, but subtitle)
• sub + g = sug- (suggestion, but subgroup)
• sub + r = sur- (surrogate, but subroutine)
• sub + f = suf- (suffer, but subfield)
• sub + s(p) = su- (suspect, suspire but subset, subspecies)

^[1]

• (under): under-, hypo-, infra-
• (almost): pene-, quasi-

• super-

• “sub-”, in OneLook Dictionary Search.
• John A. Simpson and Edmund S. C. Weiner, editors (1989), “sub-”, in The Oxford English Dictionary, 2nd edition, Oxford: Clarendon Press, →ISBN.

• Bus., SBU, UBS, USB, bus, bus.

Borrowed from Latin sub.

sub-

1. sub-

• “sub-”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007
• “sub-”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “sub-” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• Alcover, Antoni Maria; Moll, Francesc de Borja (1963), “sub-”, in Diccionari català-valencià-balear (in Catalan)

• IPA^(key): [sub ]

sub-

1. sub-

   Synonym: pod-

   ‎sub- + ‎optimální → ‎suboptimální

• “sub-”, in Slovník spisovného jazyka českého (in Czech), 1960–1971, 1989
• sub- in Slovník afixů užívaných v češtině, 2017

From Latin sub.

sub-

1. sub-

• “sub-” in Den Danske Ordbog

• Audio:

  (file)

sub-

1. sub-

From Latin sub-.

• IPA^(key): /syb/, /syp/

sub-

1. sub-

From Latin sub.

sub-

1. sub-

From

.

• “sub-”, in Dicionario da Real Academia Galega (in Galician), A Coruña: Royal Galician Academy, 2012–2026

Ultimately from Latin sub (“under”).

• IPA^(key): [zʊp]

• Audio (Germany (Berlin)):

  (file)

sub-

1. sub-

• sud- (before a letter "d")
• sum- (before a letter "m")

From Latin sub-.

sub-

1. sub-

• suc- (before c)
• suf- (before f)
• sug- (before g)
• sum- (before m)
• sup- (before p)
• sur- (before r)
• su- (before sp)
• sus- (sometimes before c or t)

From sub (“under, beneath, below”).

sub-

1. under, sub-

   Antonym: super- (most senses)

   1. Attached to verbs:
      1. denotes position: underneath

         ‎sub- + ‎scrībō (“to write”) → ‎subscrībō (“to write underneath”, “to write below”)

      2. denotes movement:
         1. (ablative movement): from underneath

            ‎sub- + ‎trahō (“to drag”, “pull”) → ‎subtrahō (“to pull”, “drag from underneath”)

         2. (allative movement): towards the underside of something, or lower part thereof, (to) underneath; (loosely) denotes regular allative movement: towards, to

            Synonym: ad- (“towards”, “to”)

            ‎sub- + ‎iaciō (“to throw”, “hurl”) → ‎subiciō (“to throw underneath”)

            ‎sub- + ‎eō (“to go”) → ‎subtrahō (“to go beneath”, or “come under”; (also) “to come towards”, “approach”)

      3. (transferred senses):
         1. secretively, privily or stealthily; (by extension, in a bad sense) evilly, wickedly, falsely, cunningly or with bad intents

            ‎sub- + ‎moneō (“to warn”, “advise”) → ‎summoneō (“to advise secretively”)

            ‎sub- + ‎-dō (“to put”, “place”) → ‎subdō (“to substitute falsely”)

         2. denotes sufferance, coping, or brooking

            ‎sub- + ‎eō (“to go”) → ‎subeō (“to undergo”, “bear”)

         3. denotes proping, supporting; (by extension) denotes helping

            ‎sub- + ‎ferō (“to hold”) → ‎sufferō (“to hold up”, “support” or “sustain”)

            ‎sub- + ‎currō (“to run”) → ‎subtrahō (“to run to help”, “to come to save”)

         4. (downtoning) lowers the intensity of the corresponding verb: a little, somewhat, vaguely

            ‎sub- + ‎timeō (“to be afraid”, “fear”) → ‎subtimeō (“to fear a little”, “be somewhat afraid”)

         5. denotes substitution

            ‎sub- + ‎faciō (“to do”, “make”) → ‎sufficiō (“to appoint as substitute”)

         6. denotes sufficiency

            ‎sub- + ‎petō (“to make for”) → ‎suppetō (“to be at hand”)

            ‎sub- + ‎faciō (“to do”, “make”) → ‎sufficiō (“to be sufficient”)

   2. In compounds, may stand for sub in a prepositional phrase

      ‎sub- (“under”) + ‎terra (“earth”) + ‎-āneus (adjective-forming suffix) → ‎subterrāneus (“subterranean, underground”)

      ‎sub- (“under”) + ‎lūna (“moon”) + ‎-āris (adjective-forming suffix) → ‎sublūnāris (“sublunar”, “sublunary”)

   3. (downtoning) Attached to adjectives, creates new adjectives of lesser intensity, having a sense like "somewhat", "slightly", "rather", "-ish"

      ‎sub- (“somewhat”) + ‎amārus (“bitter”) → ‎subamārus (“somewhat bitter”, “bitterish”)

Learned borrowing from Latin sub-.

• IPA^(key): /sub/

• Audio:

  (file)

• Rhymes: -ub
• Syllabification: sub-

sub-

1. sub- (under, beneath)

   Synonym: pod-

2. sub- (subsidiary, secondary)

   Synonym: pod-

3. sub- (almost, nearly)

   Synonym: pod-

• “sub-”, in Polish dictionaries at PWN‎^[2] (in Polish)

Learned borrowing from Latin sub-. Doublet of so-.

• (Brazil) IPA^(key): /ˈsub(i)/
• (Portugal) IPA^(key): /ˈsub(ɨ)/

sub-

1. sub- (under, beneath)

   Synonym: so-

2. sub- (subsidiary, secondary)

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

See sub, from Latin sub.

• IPA^(key): /sub/

sub-

1. sub-

Borrowed from Latin sub-. Doublet of so-, which was inherited.

sub-

1. sub-

   Synonym: so-

• “sub-”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025