scuba diving
n.
The use of scuba gear when swimming underwater, as for recreation or research.
scuba-dive′ v.
scuba diver n.
scuba diving- observer
- observingly
- obsess
- obsession
- obsessional
- obsessionally
- obsessive
- obsessive-compulsive
- obsessive-compulsive disorder
- obsessive-compulsive personality disorder
- obsessively
- obsessiveness
- obsessor
- obsidian
- obsolesce
- obsolescence
- obsolescent
- obsolescently
- obsolete
- obsoletely
- obsoleteness
- obsoletism
- obstacle
- obstacle course
- obstetric