This is the 3988th most frequent Chinese word.
作证
"作证" means "to testify" or "to give evidence."
In this sentence, '作证' is used to mean providing testimony in a legal setting.
她在法庭上作证,描述了犯罪发生的经过。
She testified in court, describing the sequence of the crime.
Here, '作证' signifies the act of becoming a witness and offering statements to clarify or support one's position.
为了证明清白,他决定向警察局作证。
To prove his innocence, he decided to give testimony to the police station.
In this example, '作证' is applied figuratively to mean providing evidence or support on the validity of a claim.