| oanständig | nasty |
| oanständighet | misconduct |
| oanständigheter | ribaldry |
| oanständigt | improperly |
| oanständigt förslag | improper suggestion |
| oansvarig | irresponsible |
| oansvarighet | irresponsibility |
| oantagbar | unacceptable |
| oantastbar | untouchable |
| oantastlig | unexceptionable |
| oanträffbar | unavailable |
| oanvänd | unused |
| oanvändbar | useless |
| oanvändbarhet | disuse |
| oanvänt militärområde | disused military site |
| OAPEC | Organization of Arab Petroleum Exporting Countries |
| oaptitlig | unpalatable |
| oartig | gross |
| oartighet | discourtesy |
| oartikulerad | inarticulate |
| oartikulerat | indistinctly |
| oas | oasis |
| Oasis | Oasis |
| OAU | Organisation of African Unity |
| oavbruten | uninterrupted |
