What is the meaning of -o?

A colloquializing suffix, typically appended to names, abbreviations of long words, or substantive uses of adjectives.

Converts certain words to faux Italian or Spanish. Can be used with Spanish el for expressions such as el stinko.

Added to verb stems to create a noun describing an error relating to the action described by the verb.

Used to form feminine nouns from verbs.

Creates a second-person singular active imperative verb form from a non-verb.

Alternative form of o

Nominal suffix. Most Esperanto nouns end in -o. (A few nouns end in -aŭ, and with some writers some feminine names end in -a.)

-thing. (correlative object ending.)

Forms result or action nouns from verbs.

Forms variants or diminutives from a few nominal roots.

postpositive form of o

forms the locative case

Used to form result or action nouns from verbs.

Used to form nouns denoting something related to the suffixed noun.

Used to form diminutives.

Third person singular demonstrative suffix, equivalent to yon or that (specifically, an object far from both the speaker and listener)

Used to make plural indefinite and definite forms for some neuter nouns

(non-standard since 1917) Used to make singular definite form for some weak feminine nouns

Used to mark plural form for strong verbs in past tense

Forms adverbs from adjectives.

Forms agent nouns from verbs.

Alternative form of -e, as used to form the first person singular present indicative of strong verbs and class I weak verbs

Alternative form of -u

a suffix indicating the first-person singular present indicative of verbs

Forms adverbs from adjectives.

used to form masculine agents from verbs

forms adverbs from adjectives

Forms adverbs from adjectives.

used to form masculine agents from verbs and nouns

Added to a clipped noun or adjective

Romanization of -𐍉

Nominal suffix. All Ido nouns end in -o.

used with a stem to form a masculine singular noun, usually a deverbal

used with a verb stem to form a past participle

used with a stem to form the first-person singular present of regular are and ere verbs and those -ire verbs that do not take -isc-

Used to form masculine nouns with various meanings:

1. forms agent nouns, positive and especially negative nicknames and other personal designations, especially in colloquial language.

   forms agent nouns, positive and especially negative nicknames and other personal designations, especially in colloquial language.

   also forms names, especially cognomina.

   also used as an ending for some inanimate nouns.

   forms adverbs

   suffixed to nouns or adjectives — originally a-stem nouns, but later nouns with other stems — forms regular first-conjugation verbs

   suffixed to third-conjugation verbs in composition, forms regular first-conjugation verbs

   forms regular third-conjugation verbs

   dative/ablative masculine/neuter singular of -us

   form feminine equivalents of given names of central Dalmatia

   Used to form genitive singulars of masculine a-stem nouns.

   Used to form genitive singulars of masculine a-stem adjectives.

   Used to form third person present tense forms in third declension verbs.

   Used to form third person past tense forms in first declension verbs.

   An illative suffix.

   -ly (used to turn an adjective into an adverb of manner)

   forms adverbs from adjectives

   forms diminutives, softening the previous consonant

   forms masculine singular nouns and adjectives

   a suffix indicating the first-person singular present indicative of -ar

   a suffix indicating the first-person singular present indicative of -er

   a suffix indicating the first-person singular present indicative of -ir

   Forms the nominative singular of vocalic oikoclitic masculine nouns

   Forms the nominative masculine singular of vocalic oikoclitic adjectives

   Attaches to the perfective stem to form the third-person singular masculine past tense of intransitive verbs

   Vocative singular

   Used with a stem to form a masculine singular noun

   suffix indicating the first-person singular present indicative of verbs

   suffix used in nominal forms of verbs in the absence of a more specific suffix (such as -aji), in conjunction with a noun class prefix

   wa class_(II), m class_(III), and u class_(XI) relative marker

   nonce suffix added for rhyming and scansion purposes

   dative suffix

   Combines with an (often clipped) word to create a noun referring to a person with a related property. Gives a familiar and to some extent diminutive nuance.

   adverb ending

   -wise (in the matter of; with regard to)

   used to form pet names

   verb suffix for the third-person singular present subjunctive

   Forms verbnouns from verb stems.

   Source: wiktionary.org