-o

-o · suffix¹

1. Latinō
2. Old Frenchoh
3. Middle Englisho
4. EnglishO
5. Middle Englisho
6. Englishoh
7. English today-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.

-o · suffix²

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.

-o · suffix³

Rebracketing of typo.