1. A transient variation in electrical voltage or current: "The lightening caused a spike in the electricity of the community which caused a loss of power in homes and businesses for over an hour."
2. Sports equipment consisting of a sharp points on the soles of shoes worn by athletes: "The golfer wanted to replace the spikes on his golf shoes."
3. A sharp increase followed by a sharp decline: "There was a spike in traffic during the rush hour so we went to a restaurant until the traffic spike decreased."

"During the last months, there have been several spikes in the prices for precious metals."

4. Women's shoes with high, thin heels: "As usual, the popular singer wore several different spikes during her musical presentation."
5. A sharp-pointed projection along the top of a fence or wall or even a dinosaur: "Mark's son tore his pants on one of the spikes on the top of the wall when he tried to climb over it."
6. A long, thin sharp-pointed implement made of wood or metal: "The cook used various kinds of spikes or knives while he was trimming the meat."
7. A large stout nail: "The carpenter used the big pointed spikes to hammer into the two-by-fours as fasteners."

"Roland was told to hammer the railroad spikes in straight and carefully into the wooden railroad ties which are the cross braces that support the metal rails on railroad tracks."

8. Etymology: according to Encarta World English Dictionary,"Origin uncertain: ultimately from an Indo-European base meaning 'sharp point,' which is also the ancestor of English spit [thin rod for roasting something], spire [tall, narrow, and pointed], and spoke [pointed object]."

1. To add alcohol or drugs to food or to drinks: "Someone spiked some of the glasses of fruit juice at the party with vodka."
2. To add something which gives interest or flavor to something: "The student spiked her assigned class report with sarcastic remarks."
3. To increase significantly in a short time: "After going down slightly, the gas prices spiked again."
4. To hit something down sharply towards the ground: "The winning point came in the final seconds when the volleyball player spiked the ball."
5. To form something into points: "It was unusual to see the fitness trainer spiking his hair."