To do or attempt something outside one's typical area of expertise.
To participate in a foray.
A brief excursion or attempt, especially outside one's accustomed sphere.
A sudden or irregular incursion in border warfare; hence, any irregular incursion for war or spoils; a raid.
To put excessive burdens upon (someone); to subject (someone) to anxieties.
To persistently bother (someone, or a group of people) physically or psychologically when such behaviour is illegal and/or unwanted, especially over an extended period.
To annoy (someone) frequently or systematically; to pester.
To trouble (someone, or a group of people) through repeated military-style attacks.