a remote or indirect consequence of some action; "his declaration had unforeseen repercussions"; "reverberations of the market crash were felt years later"
having an indicated pole (as the distinction between positive and negative electric charges); "he got the polarity of the battery reversed"; "charges of opposite sign"
the central part of a car wheel (or fan or propeller etc) through which the shaft or axle passes
a center of activity or interest or commerce or transportation; a focal point around which events revolve; "the playground is the hub of parental supervision"; "the airport is the economic hub of the area"
a conflict of opposed ideas or attitudes or goals; "a collision of interests"
an accident resulting from violent impact of a moving object; "three passengers were killed in the collision"; "the collision of the two ships resulted in a serious oil spill"
(physics) an brief event in which two or more bodies come together; "the collision of the particles resulted in an exchange of energy and a change of direction"