-ós

Inherited from Latin -ōsus. Compare Occitan -ós, French -eux, Spanish -oso.

• IPA^(key): (Central, Balearic, Valencia) [ˈos]

-ós (adjective-forming suffix, feminine -osa, masculine plural -osos, feminine plural -oses)

1. -ous, -y, -ful

   ‎greix (“grease”) + ‎-ós → ‎greixós (“greasy”)

   ‎dubte (“doubt”) + ‎-ós → ‎dubtós (“doubtful”)

   ‎verí (“poison”) + ‎-ós → ‎verinós (“poisonous”)

From -ó (present-participle suffix) + -s (adjective-forming suffix).

• IPA^(key): [oːʃ]

-ós

1. (adjective-forming suffix) Added to a verb to form an adjective expressing the permanent quality originating from the action. Several of the derived adjectives are also used as nouns.

   ‎tud (“to know”) + ‎-ós → ‎tudós (“scholar”)

• (adjective-forming suffix) Variants:

  -ós is added to back-vowel verbs

  -ős is added to front-vowel verbs

• For adjectives:

Inflection of -ós
	singular	plural
nominative	-ós	-ósak
accusative	-ósat -óst	-ósakat
dative	-ósnak	-ósaknak
instrumental	-óssal	-ósakkal
causal-final	-ósért	-ósakért
translative	-óssá	-ósakká
terminative	-ósig	-ósakig
essive-formal	-ósként	-ósakként
essive-modal	—	—
inessive	-ósban	-ósakban
superessive	-óson	-ósakon
adessive	-ósnál	-ósaknál
illative	-ósba	-ósakba
sublative	-ósra	-ósakra
allative	-óshoz	-ósakhoz
elative	-ósból	-ósakból
delative	-ósról	-ósakról
ablative	-óstól	-ósaktól
non-attributive possessive - singular	-ósé	-ósaké
non-attributive possessive - plural	-óséi	-ósakéi

• For nouns:

Inflection (stem in -o-, back harmony)
	singular	plural
nominative	-ós	-ósok
accusative	-óst	-ósokat
dative	-ósnak	-ósoknak
instrumental	-óssal	-ósokkal
causal-final	-ósért	-ósokért
translative	-óssá	-ósokká
terminative	-ósig	-ósokig
essive-formal	-ósként	-ósokként
essive-modal	—	—
inessive	-ósban	-ósokban
superessive	-óson	-ósokon
adessive	-ósnál	-ósoknál
illative	-ósba	-ósokba
sublative	-ósra	-ósokra
allative	-óshoz	-ósokhoz
elative	-ósból	-ósokból
delative	-ósról	-ósokról
ablative	-óstól	-ósoktól
non-attributive possessive - singular	-ósé	-ósoké
non-attributive possessive - plural	-óséi	-ósokéi

• Appendix:Hungarian suffixes

• -eos (slender form)

• IPA^(key): /oːsˠ/

-ós

1. Relative ending of second conjugation verbs in the future tense

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.) Compare glúcós (“glucose”).

-ós m

1. (chemistry) -ose

• Ó Dónaill, Niall (1977) “-ós”, in Foclóir Gaeilge–Béarla, Dublin: An Gúm, →ISBN