To aim for, go after (a specified objective, situation etc.).
To follow, travel down (a particular way, course of action etc.).
To follow urgently, originally with intent to capture or harm; to chase.
To participate in (an activity, business etc.); to practise, follow (a profession).
To act as a legal prosecutor.
To make a physical or mental effort to progress some specified task; to endeavor or struggle on an issue or project.