(informal) An assistant to another person, especially to a superior or more important person.

A one-wheeled attachment to the side of a motorcycle to allow for a separate seat for a passenger or cargo space. / A cocktail made with cognac (or brandy), triple sec liqueur, and lemon juice.

A line at the side of something. / Something that is additional or extra or that exists around the edges or margins of a main item.

(sports, transitive) To place on the sidelines; to bench or to keep someone out of play. / (transitive) To remove or keep out of circulation or out of the focus.

Exceptionally funny; hilarious. / (of laughter) Intensely uncontrollable and genuine.

A swimming stroke swum on the swimmer's side.

A short news story printed alongside a larger one. / A block of information placed at the side of a printed page. / (Internet) A block of information placed at the side of a webpage.

(transitive) to place (information) into a sidebar, or as if into a sidebar

(colloquial) Indicating an anagram or other approximate rearrangement of the letters in the original term.

A minor attraction at a larger event such as a circus, fair, music festival or similar. / (figuratively) An incidental spectacle that diverts attention from a larger concern.