have a habit of doing; tend to doDescribes a habitual behavior or tendency, often one that is noticeable or slightly undesirable. The verb before 癖がある indicates the behavior, and する癖がある is used when the behavior is expressed with する.
JA: 彼女は自信のないときに咳払いをする癖がある。
EN: She has a habit of clearing her throat when she feels unsure of herself.