(baseball) A fielding play where the fielders deceive the baserunners as to the location of the ball, allowing one of the fielders to attempt to tag a runner out without the runner being aware of it.

(food) Synonym of arancino

(food) Synonym of onigiri

plural of ball-and-stick model

(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).

(idiomatic, slang) The entire or overall plan, concept or action. / (idiomatic, slang) Everything of a similar or related nature; everything necessary for a particular purpose.

plural of hidden-ball trick

A kind of scooper or spoon with small hemispherical head which is useful for scooping round pieces of melon, watermelon, etc.

plural of melon ball scooper

(mathematics) A theorem stating that there is no nonvanishing continuous tangent vector field on the sphere; colloquially, that "you can't comb a hairy ball flat without creating a cowlick".