—ball /bɔːl/ aep /bɑːl/
noun [C] (DANCE)
► F0 a large formal occasion where people dance: » Did you go to the Summer Ball last year?Thesaurus+: ↑Celebrations, parties and special occasions , ↑Specific holidays and festivalsnoun [C] (ROUND OBJECT)
A1 any object in the shape of a sphere, especially one used as a toy by children or in various sports such as tennis and football:
» a beach/golf/tennis ball» Just try to concentrate on hitting the ball.» The kitten curled itself into a ball (= the shape of a ball).See picture: snooker balls 
Thesaurus+: ↑Spherical, circular and annular objects , ↑Geometrical shapesThesaurus+: ↑Toys and dolls
A1 a long piece of thread that has been rolled into a ball:
» a ball of string/woolThesaurus+: ↑Spherical, circular and annular objects , ↑Geometrical shapesF0 the rounded part of your foot or thumb where the toes join the foot and the thumb joins the hand
See picture: ball of the foot 
Thesaurus+: ↑The footThesaurus+: ↑The hand
• • •
Extra Examples:» She kicked the ball so powerfully that it flew over the hedge.» He rolled the clay into a ball in his hands.» My golf was terrible today - I just didn't strike the ball well.» The ball bounced off the post and into the net.» He wound the string into a ball.