(FWTM) The width of a Gaussian or Lorentzian type curve at the tenth of its maximum height (full width at half maximum (FWHM)) and a quality measure of the sharpness of a peak (frequency peak, resolution peak) used less frequently than the FWHM measure.

Noise distributed in a normal (Gaussian) pattern. In such a distribution, approximately 65% of all points fall within one standard deviation (s) of the mean.

See also Full Width at Tenth Maximum.