telecom vs multiplex

telecom and multiplex both are nouns.

Word	Noun	Adjective	Verb	Adverb
telecom	Yes	No	No	No
multiplex	Yes	Yes	No	No

As nouns, multiplex is a hyponym of telecom; that is, multiplex is a word with a more specific, narrower meaning than telecom:

telecom: (often plural) systems used in transmitting messages over a distance electronically
multiplex: communicates two or more signals over a common channel

Other hyponyms of telecom include telephone, telephony, telegraphy, wireless, broadcasting, phototelegraphy.

telecom (noun)	multiplex (noun)
(often plural) systems used in transmitting messages over a distance electronically	a movie theater that has several different auditoriums in the same building
	communicates two or more signals over a common channel

telecom (adjective)	multiplex (adjective)
	having many parts or aspects
	many and varied; having many features or forms