What does sinusoidal mean?
Sinusoidal is the adjective used to describe something shaped like, or changing according to, a sine wave. In mathematics and the physical sciences, a sinusoidal quantity rises and falls smoothly between a maximum and a minimum, repeating at regular intervals. This makes the term especially useful for describing alternating electrical signals, oscillations, vibrations, sound waves, and the motion of objects that repeatedly move up and down. The word is also used more broadly for curves that resemble a sine wave or for movements with a smooth, rhythmic rise and fall. In everyday writing, “wavy” may be easier to understand, but “sinusoidal” is more exact and mathematically specific. It belongs chiefly to technical and formal registers rather than ordinary conversation.
adjectiveHaving the form or character of a sine wave; varying periodically in a way described by a sinusoidal function.
- Resembling or following the shape of a sine wave; varying smoothly and periodically.
"The sensor detected a smooth, sinusoidal signal across the measured range."
"Current flowing through the circuit produced a nearly sinusoidal alternating voltage."
"The bird's flight followed a sinusoidal path as it repeatedly climbed and descended."
A sinusoidal signal rises and falls like a perfect wave, making “sinusoidal” the mathematical shorthand for smooth, repeating motion.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sinusoidal come from?
Sinusoidal was formed in the 19th century from “sine,” with the suffix “-oid,” meaning “resembling” or “like.” “Sine” comes through Old French from Latin sinus, meaning “bend” or “curved fold,” a word that also underlies terms such as “sinuous,” “sinuosity,” and “sinus.” The modern mathematical sense developed from the Latin term for the curved line associated with an angle and ultimately with the curved hollow of a wave or fold.
Related word forms
How sinusoidal is actually used
This is primarily a technical term used in mathematics, physics, engineering, and signal processing. In general descriptive writing, it is more precise than simply saying “wave-like,” but it can sound overly technical when describing an ordinary landscape or object.
Easily confused with sinusoidal
A sinusoid is a curve or function that has sinusoidal form, whereas sinusoidal is the adjective describing that form.
Sine is the trigonometric function itself, while sinusoidal describes a quantity that varies according to that function.