polyethylene vs polythene

polyethylene and polythene both are nouns.

Word	Noun	Adjective	Verb	Adverb
polyethylene	Yes	No	No	No
polythene	Yes	No	No	No

As nouns, polyethylene and polythene are synonyms defined as:

polyethylene and polythene: a lightweight thermoplastic; used especially in packaging and insulation

polyethylene (noun)	polythene (noun)
a lightweight thermoplastic; used especially in packaging and insulation	a lightweight thermoplastic; used especially in packaging and insulation