Thermoplastic
[θɜːməʊ'plæstɪk] or [,θɝmo'plæstɪk]
Definition
(noun.) a material that softens when heated and hardens again when cooled.
(adj.) having the property of softening or fusing when heated and of hardening and becoming rigid again when cooled; 'thermoplastic materials can be remelted and cooled time after time without undergoing any appreciable chemical change' .
Edited by Colin--From WordNet