chiefcause
nounUK /ˌtʃiːf ˈkɔːz/
US /ˌtʃiːf ˈkɔːz/
The chiefcause is the biggest reason why something happens.
The chiefcause of the puddle was the heavy rain.
OTHER MEANINGS
2. The most important person or thing that makes something happen.
The chiefcause of the team's win was their hard work.
3. The first or earliest reason behind a problem.
Scientists looked for the chiefcause of the sickness.
4. The main factor that explains a result.
The chiefcause of the loud noise was the old machine.