The word plasma is a Greek word which means "to be formed or moulded" (the word plastic shares the same root).

• In physics and chemistry, a plasma is an ionized gas characterized by collective electromagnetic behavior.
  • In engineering, a plasma in this sense is used in a plasma display to render pictures.
• In medicine, the fluid portion of blood is known as blood plasma, but lymph and intramuscular fluid can also be referred to as plasma (first used in 1839).
• The word may also refer to the fluid portion of milk; whey (first used in early 20th century).
• In geology, plasma is a green type of chalcedony (now rare—first used in 1772).