Peeling is calling to see one more card with a hand one should probably fold.
The flop comes. An opponent bets. The peeler looks at the bet, looks at his own cards, looks at the flop, and finally says, "Ah, I'll see one more card!" Unless he is an actor of Academy Award proportions, he's probably calling with a hand he should be folding. He's the type of player who cannot sleep at night if the next card off the deck is the one that makes his hand, and he's not there to get it. He is employing the common practice of peeling one off, and chances are, he does it far too often.