A person who brings a charge or complaint before a court of law; a complainant, a plaintiff. Obsolete.

A person who uses a service offered or provided by a professional person or a business; a client. In early use esp. with reference to the sexual…

A person who makes an earnest or humble request; one who beseeches, implores, or begs. Now somewhat rare.

A person who is overly persistent or troublesome in soliciting or making requests; an importuner.