the communication of messages directly received from God, either in biblical or modern times.
While generally taken to mean future-telling based upon special revelation from God (eg Jacob's blessings upon his sons on his deathbed at the end of Genesis), this is not always the case: it can also refer to the special insight given by God into a specific situation or personal case (eg, "the woman at the well").
Quoting from Wikipedia,
In the New Testament, prophecy is referred to as one of the Spiritual gifts given by the indwelling Holy Spirit. From this, many Christians believe that the gift of prophecy is the supernatural ability to receive and convey a message from God. The purpose of the message may be to "edify, exhort and comfort" the members of the Church. In this context, not all prophecies contain predictions about the future. The Apostle Paul also teaches in First Corinthians that prophecy is for the benefit of the whole Church and not just the individual exercising the gift.