to interfere or try to intervene in (an issue that does not concern one).

(dated, military, of gunners) To persist in faithfully attending to cannons while under fire. / (idiomatic, by extension) To maintain one’s position or viewpoint when faced with opposition.

A wrong idea about something, a misconception.

(idiomatic, informal) Used to indicate that something or someone is finished, or, in a broader sense, defeated or ruined.

(idiomatic) To concentrate on one's own tasks, affairs, area of expertise, etc., especially in order to avoid distraction, embarrassment, or other needless problems.

(idiomatic) A situation, opportunity, or outcome which is less favorable than situations, opportunities, or outcomes experienced by or available to others.

(chemistry) A molecular model of a chemical substance, displaying the three-dimensional position of the atoms (as spheres) and the bonds between them (as connecting rods).

Alternative form of stick to one's guns

(idiomatic) Emphatic form of holy crap.

plural of ball-and-stick model