a wheeled vehicle that has two wheels and is moved by foot pedals | a curved piece above the wheel of a bicycle or motorcycle to protect the rider from water or mud thrown up by the wheels |
a single complete execution of a periodically repeated phenomenon | |
a periodically repeated sequence of events | |
a series of poems or songs on the same theme | |
an interval during which a recurring sequence of events occurs | |
the unit of frequency; one hertz has a periodic interval of one second (named for Heinrich Rudolph Hertz) | |