ˈkætʃɪŋ dəˈtɛkʃən ɪˈspaɪ.əl ˈspaɪ.ɪŋ the act of detecting something; catching sight of something a police investigation to determine the perpetrator detection is hard on the feet the perception that something has occurred or some state exists early detection can often lead to a cure the detection that a signal is being received