-or

• -our (obsolete)

From Middle English -our, from Old French -eor, from Latin -ātor; reinforced by Old French -or and its source, Latin -tor, -tōrem.

• (UK) IPA^(key): /ə/
• (US) enPR: ər, IPA^(key): /ɚ/
• Homophones: -er, -a (in non-rhotic accents)

-or

1. Creates an agent noun, often from a verb, indicating a person or object (often machines or parts of them) that do the verb or part of speech with which they are formed.

   Synonyms: -er, (casual) -ster

   Hyponyms: -a, -ess, -ette, -rix

   Coordinate term: (converse form; one who receives from the actor) -ee

   ‎settle + ‎-or → ‎settlor

   ‎survive + ‎-or → ‎survivor

2. (electrical science) Appended to the names of members of classes of components, especially those that have an extensive property name of the same root suffixed with -ance

   Resistors possess resistance and inductors possess inductance.

In Latin-derived words, English generally appends this suffix where Latin would do it—to the root of a perfect passive participle (i.e. past participle). For other words, English tends to use the suffix -er. Occasionally both are used (protester vs. protestor).

• -er (alternative spelling)
• -rix (feminine form)

• -ist

From Latin -or.

-or

1. Used to form nouns of quality, state, or condition.

   ‎err + ‎-or → ‎error

• R&O, RO, r/o

-or m (feminine singular -ore, masculine plural -orë, feminine plural -ore)

1. forms relational adjectives and demonyms

   ‎Mirditë + ‎-or → ‎mirditor (“inhabitant of Mirdita”)

2. forms agent nouns

   ‎dasmë (“wedding”) + ‎-or → ‎dasmor (“wedding guest”)

3. forms many names for months

• Formation with the article in the standard language is often based on Gheg roots, e.g.:

  ‎zâ + ‎-or → ‎zanor, rather than from zë

  ‎shkretinë + ‎-or → ‎shkretinor, rather than from shkretëtirë

• -ësor

Inherited from Latin -ōrem.

-or f (noun-forming suffix, plural -ors)

1. used to create abstract nouns from adjectives; -ness

   ‎blanc (“white”) + ‎-or → ‎blancor (“whiteness”)

   ‎buit (“empty”) + ‎-or → ‎buidor (“emptiness”)

• “-or”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2024
• “-or” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.

Inherited from Latin -ōrem m.

-or f (plural -ors) (ORB)

1. Attaches to an adjective denoting a physical property to form the associated abstract noun.

Modeled after -ar and -os.

-or

1. Used to denote the future infinitive of a verb.

   Tu mustas kompror lakto kande tu es che la butiko.

   You must buy milk when you are at the shop.

• -ar (present infinitive tense)
• -ir (past infinitive tense)

• (Classical) IPA^(key): /or/, [ɔr]
• (modern Italianate Ecclesiastical) IPA^(key): /or/, [ɔr]

From Proto-Italic *-ōs, from Proto-Indo-European *-ōs, for original *-oss, compound suffix from *(é)-os (athematic) (neuter s-stem) +‎ *-s (masculine nominative).

The ō from the nominative case was made common to all cases originally with non-ablauting o (the three exceptions were arbor, mulier and Cerēs). Afterwards nom.sg. -ōr > -or, by Latin sound laws. Thus paradoxically, as in other r-stems (soror, -tor), in the resulting paradigm the one form with a short stem vowel is the only form whose stem was etymologically long.[1]

-or m (genitive -ōris); third declension

1. used to form a third-declension masculine abstract noun from a verb root or conceived root form

   Synonyms: -ēs, -us

   ‎amō (“I love”) + ‎-or → ‎amor (“love”)

   ‎timeō (“I fear”, “I am afraid”) + ‎-or → ‎timor (“fear”)

Third-declension noun.

• -ātor
• -tor (-sor)

• Italo-Romance: m
  • Italian: -ore
• Gallo-Romance: f
  • Catalan: -or
  • Franco-Provençal: -or
  • French: -eur
  • Occitan: -or
• Ibero-Romance: m
  • Spanish: -or

See the etymology of the corresponding lemma form.

-or

1. first-person singular present passive indicative of -ō (first conjugation)

See the etymology of the corresponding lemma form.

-or

1. first-person singular present passive indicative of -ō (third conjugation)

-or

1. A plural marker, used on feminine gender nouns ending with an unstressed -e [-a].

The -or suffix is a bracket form in Nynorsk whereas -er is the main form. In Bokmål, -er is the only form allowed suffix.

• IPA^(key): /or/

From Proto-Germanic *-ar-. Akin to Old High German -ar.

• -er

-or

1. suffix forming adjectives from verbs denoting tendency or causation

   ‎slīpan (“to slip, glide”) + ‎-or → ‎slipor (“slippery”)

   ‎wacian (“to be awake, be watchful”) + ‎-or → ‎wacor (“vigilant, watchful”)

• English: -er

From Proto-Germanic *-raz. Akin to Old Saxon -or, Old High German -ur.

-or

1. Suffix variant found on masculine a-stem nouns

   ‎ċeole (“throat”) + ‎-or → ‎ċeolor (“collar, throat”)

   ‎eald (“old”) + ‎-or → ‎ealdor (“chieftain, ruler”)

   ‎siġe (“victory”) + ‎-or → ‎sigor (“victory”)

   ‎telga (“branch, bough”) + ‎-or → ‎telgor (“branch, twig”)

   ‎dæġ (“day”) + ‎-or → ‎dōgor (“day”)

   ‎sele (“hall”) + ‎-or → ‎salor (“hall, palace”)

From Latin -(a)tor.

• -eor, -eour, -eur
• -our (late Anglo-Norman)
• -ur (early Anglo-Norman)

-or (nominative singular -ere, occasionally -ors)

1. -er, suffix used to form agent nouns

• → Middle English: -our (in part)
  • English: -or (-er)
  • Scots: -or (-er)

From Latin -or.

• -eur
• -our (late Anglo-Norman)
• -ur (early Anglo-Norman)

-or (nominative singular -or)

1. -ness, indicates a quality, a characteristic

   ‎blanche + ‎-or → ‎blanchor (“whiteness”)

• Middle French: -eur (both etymologies)
  • French: -eur (both etymologies)
• Norman: -eux
• → Middle English: -our (in part)
  • English: -or (-er)
  • Scots: -or (-er)

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

• IPA^(key): /ɔr/
• Rhymes: -ɔr
• Syllabification: or

-or m inan

1. forms augmentatives

   ‎język + ‎-or → ‎jęzor

• -or in Polish dictionaries at PWN

-or (Cyrillic spelling -ор)

1. Suffix appended to words to create a masculine noun, usually denoting a profession or a performer, used chiefly for words of Latin origin.

• -ator

Inherited from Latin -or.

-or m (noun-forming suffix, plural -ores)

1. forms abstract nouns from adjectives

   ‎dulce + ‎-or → ‎dulzor

-or m (noun-forming suffix, plural -ores, feminine -or, feminine plural -ores)

1. Used to create agent nouns from verbs

   ‎revisar + ‎-or → ‎revisor

• “-or”, in Diccionario de la lengua española, Vigésima tercera edición, Real Academia Española, 2014

Usually corresponds to Icelandic -ur (if plural) and dialectal Norwegian Nynorsk -ur or -o.

• IPA^(key): /ʊr/, [ʊᵝr]

-or

1. A plural marker. This marker is the regular plural for common gender nouns ending with an unstressed -a. Such an -a disappears when -or is added. The marker is used, however, with a few other nouns as well.

   ‎docka (“doll”) + ‎-or → ‎dockor (“dolls”)

   ‎våg (“wave”) + ‎-or → ‎vågor (“waves”)

• ro

Cf. Latin -ārius.

• IPA^(key): /ɔr/

-or m (plural -orion)

1. person or man associated with root

   Synonyms: -wr, -ydd

   ‎telyn (“harp”) + ‎-or → ‎telynor (“(male) harpist”)

   ‎llên (“literature”) + ‎-or → ‎llenor (“literary man, man o letters”)

   ‎carchar (“prison”) + ‎-or → ‎carcharor (“prisoner”)

R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke et al., editors (1950–present), “-or”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies