| English | Finnish |
| open dump | luvaton kaatopaikka |
| Open-Ended Working Group | avoin työryhmä |
| open flame | avotuli |
| open lawn | nurmi |
| open lawn Any relatively unobstructed field of cultivated and mown grass, especially near a house or in a park | nurmi |
| Open Partial Agreement on Major Hazards EUR-OPA | avoin osittainen sopimus, joka koskee suojaamista, ennaltaehkäisyä ja avun organisointia suurten riskien varalta |
| Open partial agreement on the prevention of, protection against, and organisation of relief in major natural and technological disasters | avoin osittainen sopimus, joka koskee suojaamista, ennaltaehkäisyä ja avun organisointia suurten riskien varalta |
| open sea The high seas lying outside the exclusive economic zones of states. All states have equal rights to navigate, to overfly, to lay submarine cables, to construct artificial islands, to fish, and to conduct scientific research within the high seas | avomeri |
| open sea and tidal areas | avomeri- ja vuorovesialueet |
| open sea fishing | avomerikalastus |
| open sea fishing Fishing in the deepest parts of the sea | avomerikalastus |
| quiet area in open country | hiljainen rakentamaton alue |
| worked-out open cut | loppuun louhittu avolouhos |
| worked-out open cut A mine where all the mineral that could be profitably exploited has been removed | loppuun louhittu avolouhos |
