Would you describe a man with one hair on his head as bald? Yes. Would you describe a man with two hairs on his head as bald? Yes. … However a man with ten thousand hairs on his head isn’t bald. So where do you draw the line? How many hairs can a man have before he isn’t bald any more?
If you want something more detailed you might enjoy this http://plato.stanford.edu/entries/sorites-paradox/