adverb
by chance; accidentally; happen to
Describes an unintended or coincidental event. Often used when something occurs without planning or expectation.
駅でたまたま高校の友達に会った。
I happened to run into a high school friend at the station.
たまたま通りかかったら、事故を見てしまった。
I happened to be passing by and saw the accident.
adverb
Indicates an infrequent but recurring event. Similar to たまに, but たまたま can also carry a nuance of chance occurrence.
See also: たまに
彼はたまたまこの店に顔を出す。
He occasionally shows up at this shop.