by chance
US /baɪ tʃæns/
UK /baɪ tʃæns/
1.
偶然に, たまたま
without planning or intention; accidentally
:
•
I met my old friend by chance at the airport.
空港で旧友に偶然会った。
•
Did you find that book by chance or were you looking for it?
その本は偶然見つけたの、それとも探していたの？