electronic equipment that converts sound into electrical signals that can be transmitted over distances and then converts received signals back into sounds; "I talked to him on the telephone"
a board game in which players try to gain a monopoly on real estate as pieces advance around the board according to the throw of a die
exclusive control or possession of something; "They have no monopoly on intelligence"
(economics) a market in which there are many buyers but only one seller; "a monopoly on silver"; "when you have a monopoly you can ask any price you like"
an obstruction that stands in the way (and must be removed or surmounted or circumvented)
something immaterial that stands in the way and must be circumvented or surmounted; "lack of imagination is an obstacle to one's advancement"; "the poverty of a district is an obstacle to good education"; "the filibuster was a major obstruction to the success of their plan"