What is the history or origin of the elememt name lead?

The Latin wordPlumbum means literally "soft metal". Lead was referred to as Plumbum Nigrum (black soft metal) in contrast to Tin which was called Plumbum Candidium (Bright soft metal). Tin however, became known as Stannum, which was originally a name for an alloy of Tin and Silver.

Sources:

http://en.wikipedia.org/wiki/Tin

http://en.wikipedia.org/wiki/Lead