noun: generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or used for making e.g. coatings and adhesives
adjective: used of the imagination
Example: "Material...transformed by the plastic power of the imagination--Coleridge"
adjective: capable of being influenced or formed
Example: "The plastic minds of children"
adjective: capable of being molded or modeled (especially of earth or clay or other soft material)