What is the meaning of ō?

A common convention for a long vowel o

A dictionary transcription for the GOAT vowel

cloud

A letter of the Halkomelem alphabet, written in the Latin script.

news

The twenty-third letter of the Livonian alphabet, written in the Latin script.

Hanyu Pinyin reading of 喔

Hanyu Pinyin reading of 噢

Hanyu Pinyin reading of 呵

The twelfth letter of the Māori alphabet, written in the Latin script.

possessive article used before a pronoun, like the functions of and -’s in English

to have, to own

food, provisions

thy, your

rabbitfish

food, provisions, rations

A greeting said when answering the telephone, much like the English hello.

Rōmaji transcription of おう

Rōmaji transcription of おお

Rōmaji transcription of オー

The twenty-fifth letter of the Latgalian alphabet, written in the Latin script.

The twenty-first letter of the Samogitian alphabet, called ėlguojė ō and written in the Latin script.

The name of the Latin script letter O/o.

The twenty-first letter of the Silesian alphabet, written in the Latin script.

alternative form of ö

Source: wiktionary.org