12-Letter Nouns Starting With O
Here's the list of all the 388 12-Letter Nouns Starting With O in the English Language.
The list is arranged by the word lengths. Click on the length below to jump to the relevant section of the page.
| Common Nouns (with Definitions and Examples) | |
|---|---|
| organization | 1. a group of people who work together 2. an organized structure for arranging or classifying More Definitions → |
| organisation | 1. the persons (or committees or departments etc.) who make up a body for the purpose of administering something 2. a group of people who work together More Definitions → |
| optimization | 1. the act of rendering optimal More Definitions → |
| osteoporosis | 1. abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium; most common in postmenopausal women More Definitions → |
| optimisation | 1. the act of rendering optimal More Definitions → |
| oceanography | 1. the branch of science dealing with physical and biological aspects of the oceans More Definitions → |
| orthopaedics | 1. the branch of medical science concerned with disorders or deformities of the spine and joints More Definitions → |
| oscilloscope | 1. electronic equipment that provides visual images of varying electrical quantities More Definitions → |
| orthodontics | 1. the branch of dentistry dealing with the prevention or correction of irregularities of the teeth More Definitions → |
| obsolescence | 1. the process of becoming obsolete; falling into disuse or becoming out of date More Definitions → |
| overestimate | 1. an appraisal that is too high 2. a calculation that results in an estimate that is too high More Definitions → |
| orthodontist | 1. a dentist specializing in the prevention or correction of irregularities of the teeth More Definitions → |
| overexposure | 1. the act of exposing film to too much light or for too long a time 2. the act of exposing someone excessively to an influencing experience More Definitions → |
| obstetrician | 1. a physician specializing in obstetrics More Definitions → |
| osteosarcoma | 1. malignant bone tumor; most common in children and young adults where it tends to affect the femur More Definitions → |
| obliteration | 1. destruction by annihilating something 2. the complete destruction of every trace of something More Definitions → |
| ossification | 1. the developmental process of bone formation 2. the calcification of soft tissue into a bonelike material More Definitions → |