We don't have synonyms for sinewave yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are sine wave, sine-wave and timewave.
(n) :
Alternative form of sine wave. [(trigonometry, signal processing) A periodically oscillating waveform as described by the sine function, possibly multiplied by some amplitude, shifted by some phase, and translated by an additive constant.]
(n) :
Alternative form of sine wave. [(trigonometry, signal processing) A periodically oscillating waveform as described by the sine function, possibly multiplied by some amplitude, shifted by some phase, and translated by an additive constant.]