# ob vs oo

> English confusable word pair

## The two words

### ob
*noun · IPA /ɒb/ · frequency rank #16,547*
a halfpenny

### oo
*noun · frequency rank #13,572*
(Ω, ω) The Greek letter omega.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/ob-vs-oo