polyethylene noun poly??eth??yl??ene \??p??l-??-??eth-??-??l??n\ (Medical Dictionary)Medical Definition of POLYETHYLENE : a polymer of ethylene; especially : any of various lightweight thermoplastics (CH2CH2)x that are resistant to chemicals and moisture and are used especially in packaging, insulation, surgical implants, prostheses, and tubing Learn More About POLYETHYLENE SCRABBLE??: Playable wo