Definition of "sine-wave" []

• A wave in which the vibrations of the particles of the transmitting medium are simple harmonic motions. (noun)

The Century Dictionary (Public Domain)

• "You can see how jagged and incoherent the heart rhythm pattern is when you're anxious or frustrated and how smooth and sine-wave like (coherent) it becomes when you're feeling appreciation."
• "The proportions are the same, in that the sine-wave usually peaks mid-week and declines through Sunday, going back up again on Monday."
• "The system bobs above and below the plane in a sine-wave pattern reaching around 65-70 light years above and below."