Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. The word solder comes from the Middle English word soudur, via Old French solduree and soulder, from the Latin solidare, meaning "to make solid". In fact, solder must be melted in order to adhere to and connect the pieces together, so a suitable alloy for use as solder will have a lower melting point than the pieces it is intended to join. Whenever possible, the solder should also be resistant to oxidative and corrosive effects that would degrade the joint over time. Solders intended for use in making electrical connections between electronic components also usually have favorable electrical characteristics.