Actually 95Bravo, that is a GREAT question, one that will be difficult for anyone to properly answer. The word 'Bowie' is used for a great range of knives having very different features.
Since the name 'Bowie knife' arose associated with a notorious knife fight in early America, involving a certain Jim Bowie who may (or may not) have commissioned a knife designed to his particular specifications, the 'Bowie' knife can be broadly described as a 'large butcher knife', which (at least in Jim Bowie's case) was used to rapidly dispatch an opponent with one single upward thrust to the belly, diaphragm, and heart. One stroke. One dead man. It was a most impressive death, and caught the attention of both newspaper reporters and the general public.
However, nobody really knows exactly what sort of knife Jim Bowie was carrying the night of the 'sand-bar' duel.
So, all we can really say is that a Bowie knife is a fighting knife. Generally, this means a blade about 8 to 11 inches long, with a guard, and a handle a varying proportions. Most include a 'clip' point, ideal for thrusting, but this is not necessarily historically accurate.
Most modern makers make knives in this size range. Those with a clip point, designed for light-weight, speed, and thrusting, are usually called 'Bowie knives.' Those in the same size range with a drop or straight point emphasizing chopping utility as opposed to thrusting, are often called camp knives.
So I would call a Bowie knife almost anything in the 8 to 11 inch blade range, with a distal taper and a clip point, with a balance near or even behind the guard, a 'Bowie', or 'fighting' knife.
But I am sure others will disagree.
Let the fun begin...
Para