Then there is a question of how soluble is the substance. We may say that lead chloride is insoluble in water. In actual fact there is still a very very small amount of it dissolved in the water. When we compare solubility it is a relative term. The temperature is also very important and must be specified when we talk about solubility.
Lead chloride is insoluble in cold water but readily dissolves if the water is heated.
I hope that answers your question.