A wrong idea about something, a misconception.

(UK) Wholesomely athletic and enthusiastic, in a manner stereotypically associated with traditional British public schools for girls.

(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).

A game in which players attempt to remove sticks from a scattered pile without disturbing any stick other than the one currently being removed.

Alternative form of stick to one's guns

(idiomatic) Emphatic form of holy crap.

plural of ball-and-stick model