Definition of float
A float is usually done in position. A float calls a player's bet in order to bluff him later in the hand. The player who float may have a marginal hand with little opportunity for improvement. But he call is in position because he knows the player he is playing against is face up or because he thinks he can bluff him later in the hand. Do not shuffle float and chase. When we hunt, we call in order to hit our draw. When we float, we call in order to bluff later in the hand.
Is it a float or a nuts?
A good player that float will be hard to beat. A float is played as if you have a nuts (the best possible hand). If you have 99 out of 992, turn 5 and river 6, you will probably call flop, call the turn and raise the river. If you're on float, you'll play exactly the same way, but bluff. By calling, you keep your rank higher in the eyes of your opponent. And if a draw hits, you can still represent it if you were bluffing. You won't see many tens at the low limits, but more at the medium and high limits.