principalreason
nounUK /ˈprɪn.sə.pəl ˈriː.zən/
US /ˈprɪn.sə.pəl ˈriː.zən/
The main reason is the biggest or most important why something happens.
The principal reason we left early was that it started to rain.
RELATED WORDS
OTHER MEANINGS
2. The most important cause behind a decision.
The principal reason for choosing the blue car was its low price.
3. The leading explanation given for an event.
The principal reason for the delay was a broken train.
4. The main factor that makes something happen.
The principal reason for her success is hard work.