What is a "prophetic word"? Is it truly scriptural? Where is this mentioned in the New Testament? These practices that surround spiritual gifts are a bit confusing, to say the least. I'm skeptical, but open.
A prophetic word, sometimes known as a word of knowledge, is a prophecy given to a worshipper by God for the congregation. It might come ecastatically (in tongues, for instance) and need another's interpretation, or come in the language of the assembly, not necessarily 'miraculously'. Its hearers then weigh it to discern whether it truly is from God. They weigh it according first to Scripture, then to whether it is edifying rather than disruptive, and so on. If so, it is taken as God's message to that body. It is not binding on other believers, for only the Bible is God's word to the whole Church.
Is it truly biblical? I can think of lots of reasons to say yes, and no real reasons to say no. The Old Testament prophets, especially the apocalyptic ones, are exercising this gift. Jesus appeals to Isaiah 61 as announcing his own prophetic ministry (Luke 4:18). Paul affirms it in 1 Cor. 12:8 and regulates it in 1 Cor. 14:26-33 so that it serves the needs of the whole congregation, not just a spiritual 'elite'. (It may be that the Gentile Christians of his churches were bringing unhelpful Greek notions of ecstatic speech to the practice of prophesying.) When pressed Paul will cite (his own?) ecstatic experiences (2 Cor. 12:2). Both the disciples' speeches at Pentecost and Peter's sermon viewing it in terms of Joel 2:28-32 (Acts 2) are also instances of it (Acts 2:17). The practice is the occasion for Revelation: "write what you see," Jesus says to John the prophet (Rev. 1:19). An apostle's daughters do it (Acts 21:9).
The early church finds other ways to respect and regulate the practice. For an example, see the Didache 11-13. This is a very early (70-200 AD) and influential document, sometimes taken by early Christians as Scripture but ultimately left out of the New Testament. It shows us a first- and century-church that was hierarchical, liturgical, ethically focused, and charismatic.
With the rise of a second century group called Montanists, the mainstream (that is, Catholic) Church worried about the practice. Montanists treated their prophecies as on a par with the apostolic scriptures. In reaction, the rest of the Church shut them down. This had a real chilling effect on the practice. It never died out entirely, but it did become something done more rarely, quietly, and cautiously. Prominent theologians argued that these gifts had ceased since the era of the apostles. That school of thought ("cessationism") became the dominant view among Protestants, whereas Catholics remained more comfortable with affirming miracles of many kinds. Nineteenth century Dispensationalism found even more rigorous (and in my opinion indefensible) reasons to relegate certain gifts to certain 'ages and dispensations'. The Pentecostal movement of the twentieth century restored the practice to its early prominence; in some congregations, arguably to more than its early prominence. (As you can see from where the circles break on that chart, charismatics can still theoretically be Dispensationalists. But it makes for strange bedfellows.)
Theologically, I affirm these kinds of spiritual gifts on Christological grounds. Jesus promised that the Holy Spirit would empower his disciples to do his signs and wonders and mighty works, and even greater ones, and it seems to me this demands that we expect and respect such continuities between Jesus' work, the early apostolic Church's work, and the contemporary apostolic Church's work. (All Christians consider their churches 'apostolic'; I am not referring only to one Pentecostal tradition here.) There is a direct line connecting Israel, Jesus, Spirit, and Church. Moreover, I am simply unconvinced by cessationist arguments. They seem forced on the Bible rather than natural to it.
I don't have that gift, nor the gift of tongues, but I know people who do, and who use those gifts well in the service of God and neighbor.
I also know about abuses. Wackos are always ruining everything. But we don't let centuries of abusive preaching talk us out of sermons every Sunday. Paul didn't let Corinthian abuses shut down these gifts, and I won't either.