Literally, the term means by or for one party. Ex parte proceedings in court are usually permitted only when there is an emergency or an urgent matter where a notice requirement might subject the moving party to harm that could not be remedied. An example is a motion for a temporary restraining order - if both sides are required to be notified, the danger might already become a reality and the issue would be moot. When appropriate, it is a permitted exception that falls within the legal concept of due process.