This is the verse translation, not a definition of the individual word.
The Messenger believes in what has been sent down to him from his Lord, as do the believers. All of them believe in Allah, His angels, His Books, and His messengers, [saying], “We make no distinction between any of His messengers.” And they say, “We hear and obey. Grant us Your forgiveness, our Lord, and to You is the [final] destination.”