a forceful forward rush or flow; "from the bow she stared at the mesmerising onrush of the sea where it split and foamed"; "the explosion interrupted the wild onrush of her thoughts"
the quality imparted to voiced speech sounds by the action of the resonating chambers of the throat and mouth and nasal cavities
a vibration of large amplitude produced by a relatively small vibration near the same frequency of vibration as the natural frequency of the resonating system
an excited state of a stable particle causing a sharp maximum in the probability of absorption of electromagnetic radiation