| open contest | offener Wettbewerb |
| open country | Feld |
| open cover | offene Überdeckung |
| open coverage type | offene Bauweise |
| open credit | Kontokorrentkredit |
| open credit line | offene Kreditlinie |
| open cross-country race | Volkslauf |
| open crotch brief | Slip ouvert |
| open crotch briefs | Slip ouvert |
| open crotch C-string | C- String ouvert |
| open crotch G string | String-Tanga ouvert |
| open crotch G-string | G-String ouvert |
| open crotch panties | Slip ouvert |
| open crotch panty | Slip ouvert |
| open crotch string | String ouvert |
| open crotch thong | String-Tanga ouvert |
| open crown | Krone ohne Bügel |
| open cup bra | BH ouvert |
| open cut mine | Abbaustelle |
| open cut technique | offene Tunnelbauweise |
| open cut tunnel | Tunnel in Schlitzlage |
| open cycle | offene Proßeßführung |
| open D tuning | offene D-Stimmung |
| open dam | offene Sperre |
| Open Data-Link Interface | Open Datalink Interface |
| Open Database Connectivity | Open Database Connectivity |
| open day | Elternsprechtag |
| Open de Tenis Comunidad Valenciana | ATP Valencia |
| open diapason | Prinzipal |
| open die | Sattel |
| open die forging | Freiformschmieden |
| Open Directory Project | Open Directory Project |
| open distributed processing | Offene verteilte Verarbeitung |
| open door | offene Tür |
| Open Door Policy | Politik der offenen Tür |
| Open Doors | Open Doors |
| open drainage | offene Drainage |
| open drug scene | offene Drogenszene |
| Open dump | Müllhaufen |
| open dumping | Abkippen |
| Open economy | Offene Volkswirtschaft |
| Open educational resources | Open Educational Resources |
| open end spanner | Gabelschlüssel |
| open enemy | offener Gegner |
| open fabric structure | offene Gewebestruktur |
| open field | Freiland |
| open field trial | offener Feldversuch |
| open fields | Flur |
| open fifth | leere Quinte |
| open finishing | Breitausrüstung |
| open fire | schießen |
| open fire on sb. | das Feuer auf jdn. eröffnen |
| open flank | flankenoffen |
| open fold | flache Falte |
| Open format | Offenes Format |
| open fracture | offene Fraktur |
| open freight car | offener Güterwagen |
| open from 9 to 6 | geöffnet von 9 bis 6 |
| Open from 9 to 6. | Geöffnet von 9 bis 6. |
| open front bra | BH ouvert |
| open front panties | Slip ouvert |
| open front panty | Slip ouvert |
| open front press | Einständer-Exzenterpresse |
| Open front rounded vowel | Gerundeter offener Vorderzungenvokal |
| Open front unrounded vowel | Ungerundeter offener Vorderzungenvokal |
| open furnace arrangement | offene Brennkammer |
| Open Game | Offene Spiele |
| Open Gaming License | Open Gaming License |
| open grave | Grube |
| open groove | offenes Kaliber |
| open ground | Freigelände |
| open handed | freigebig |
| open heart surgery | Offenherzchirurgie |
| open hearth | Herdfeuer |
| Open hearth furnace | Siemens-Martin-Ofen |
| Open Hearts | Open Hearts |
| open hostility | offene Feindschaft |
| open house | Tag |
| Open house day | Tag der offenen Tür |
| Open Innovation | Open Innovation |
| Open Invention Network | Open Invention Network |
| Open Inventor | Open Inventor |
| open issue | Pendenz |
| open issues | Pendenzen |
| open item | offener Posten |
| open items list | Mängelbericht |
| open items list (US), deficiency report, lack report | Mängelbericht |
| open jam sandwich | Marmeladebrot |
| open jam sandwiches | Marmeladebrote |
| open jaw flight | Gabelflug |
| open jaw flights | Gabelflüge |
| open kitchen | einsehbare Küche |
| open lacing | offene Schnürung |
| open land | Freiland |
| open land requirement | Landschaftsbedarf |
| open lawn | offene Rasenfläche |
| open letter | offener Brief |
| open link | Open Link |
| open link chain | Schakenkette |
| open link chains | Schakenketten |
| open listening | Lauthören |
