1. an excited state of a stable particle causing a sharp maximum in the probability of absorption of electromagnetic radiation
2. 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
3. having the character of a loud deep sound; the quality of being resonant
4. relation of mutual understanding or trust and agreement between people
5. the quality imparted to voiced speech sounds by the action of the resonating chambers of the throat and mouth and nasal cavities