(idiomatic) A period of exceptionally hot weather. / (US, weather broadcasting) Three consecutive days with daytime high temperature of 90 degrees Fahrenheit or higher.

A large and sudden rise and fall in the tide. / (proscribed) A large, sudden, and disastrous wave of water caused by a tremendous disturbance in the ocean; a tsunami. (See Usage notes below.)

(idiomatic) Discussion or argumentation involving approximation, vagueness, educated guessing, or the attempt to explain or excuse vagaries.

(physics) A wave that can be modulated, either in amplitude, frequency, or phase, to carry or transmit images, music, speech, or other signals.

Alternative spelling of hand waving

Alternative spelling of handwaving

(physics) electromagnetic radiation having a wavelength between about .5 centimeters and 30,000 meters; used for the broadcasting of radio and television signals.

(physics) Electromagnetic radiation, such as light and radio waves.

(neurology) An electrical signal produced by the brain while the subject is relaxed.

(neurology) An electrical signal produced by the brain while the subject mentally active.