Meanings
-o1
plural -os · plural -oes · comparative more -o · superlative most -o · alternative -oh
- historicalA vocative or exclamative particle appended to street cries, nautical calls, or names to project a hail or shout.
milk + -o → milko
1 more example
smoke + -o → smoko
- A colloquializing suffix, typically appended to names, abbreviations of long words, or substantive uses of adjectives.
kid + -o → kiddo
3 more examples
sick + -o → sicko
ugly + -o → uggo
Adrian thought it worth while to try out his new slang. ‘I say, you fellows, here’s a rum go. Old Biffo was jolly odd this morning. He gave me a lot of pi‐jaw about slacking and then invited me to tea. No rotting! He did really.’
1991, Stephen Fry, chapter III, in The Liar, London: William Heinemann, →ISBN, page 26
-o2
-o3
Origin
-o · suffix
- Latinō
- Old Frenchoh
- Middle Englisho
- EnglishO
- Middle Englisho
- Englishoh
- English-o
Originally a special use of the interjection O or oh appended to street cries and nautical calls to project a hail or shout (as in milk-oh, smoke-oh, and sail-ho). Its later use as a colloquializing noun suffix, particularly prominent in Australian English, developed from the substantivation of these cries (e.g., smoko), reinforced by early nautical adaptations of Mediterranean Lingua Franca or pseudo‐Spanish words (such as guardo). As noted by the Australian National Dictionary, this vocative “hailing” origin naturally led to its frequent attachment to personal names to form nicknames (e.g., John‐o, Jacko). Some senses may also derive from o (“one”), from Middle English o, oo, a variant of a, on, oon, an (“one”). See one and -y.
More words from Middle English
Full word history & related roots →-o · suffix
From many Spanish or Italian words that end in o. This ending in such Spanish or Italian words generally derives from -um, the accusative singular inflectional ending for masculine and neuter nouns in Latin.
Full word history & related roots →Rhymes & wordplay
Sounds the same
Cite this entry
-o. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/-o
“-o.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/-o. Accessed November 2, 2026.
WatkinsX Dictionary, s.v. “-o,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/-o.
Source: -o on Wiktionary, CC BY-SA 4.0.