conventional bulbs

The round light bulbs that most people use are technically called "incandescent bulbs". However, you can also call them "conventional bulbs". The word "conventional" means that they're the kind that are most commonly used. Some other "conventional" things include:

conventional medicine (medicine done by trained doctors in clinics or hospitals)

conventional weapons (missiles, bullets, jets, etc.; not nuclear, chemical, or biological weapons)

conventional methods (of doing something)

This phrase appears in these lessons: