- without advance planning;
"they met accidentally"
- of a minor or subordinate nature;
"these magnificent achievements were only incidentally influenced by Oriental models"
- without intention; in an unintentional manner;
"she hit him unintentionally"
- The traffic accident was born almost accidentally.
- She accidentally erased the tape.
- They said that all the injuries were inflicted accidentally.
- He accidentally nudged the gatepost with the front of the car.
- by chance偶然
- by accident偶然
- by mistake错误地
- out of the blue出乎意料地