-illo

• (Classical Latin) IPA^(key): /ˈil.loː/, [ˈɪlːʲoː]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈil.lo/, [ˈilːo]

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

-illō (present infinitive -illāre, perfect active -illāvī, supine -illātum); first conjugation

1. Forms diminutive verbs from verbs.

   focilō (“I refresh, resuscitate”), less commonly focillō, from the noun focus.

   cantillō (“I hum, warble”), from the verb cantō

¹At least one use of the archaic "sigmatic future" and "sigmatic aorist" tenses is attested, which are used by Old Latin writers; most notably Plautus and Terence. The sigmatic future is generally ascribed a future or future perfect meaning, while the sigmatic aorist expresses a possible desire ("might want to"). It is also attested as having a rare sigmatic future passive indicative form ("will have been"), which is not attested in the plural for any verb.
²The present passive infinitive in -ier is a rare poetic form which is attested.

See the etymology of the corresponding lemma form.

-illō

1. dative/ablative masculine/neuter singular of -illus

• -illa (with feminine nouns)

Inherited from Old Spanish -iello, from Latin -ellus, an extension of -lus.

• Syllabification: -i‧llo

-illo m (noun-forming suffix, plural -illos)

1. added to masculine nouns to denote a diminutive form

   Synonyms: -ito, -cito, -cillo, -ecillo, -cecillo, -ico, -ín, -lito

   Coordinate term: -illa

• If the noun has a final vowel (usually -o), it is dropped before adding -illo.
• In most cases, -illo is used simply to indicate a small or endeared thing, without changing the basic meaning of the noun; however, in some cases, it is used to effect a greater change in meaning, such as bolsillo (“pocket”), from bolso (“handbag, purse”).
• Different nouns tend to prefer different diminutive suffixes (see synonyms below), though some nouns accept multiple diminutives, and there is often regional or personal variation.
• For masculine nouns ending in -a, there is some alternation between the gender-reflecting diminutive -illo and the ending-reflecting diminutive -illa. When the latter is used, -ill- may be considered an infix.

• -cillo, -ecillo, -cecillo

• “-illo”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.7, Royal Spanish Academy [Spanish: Real Academia Española], 2023 November 28