cellular telephone vs cellphone

cellular telephone and cellphone both are nouns.

Word	Noun	Adjective	Verb	Adverb
cellular telephone	Yes	No	No	No
cellphone	Yes	No	No	No

As nouns, cellular telephone and cellphone are synonyms defined as:

cellular telephone and cellphone: a hand-held mobile radiotelephone for use in an area divided into small sections, each with its own short-range transmitter/receiver

Other synonyms of cellular telephone include cell, cellular phone, mobile phone.

cellular telephone (noun)	cellphone (noun)
a hand-held mobile radiotelephone for use in an area divided into small sections, each with its own short-range transmitter/receiver	a hand-held mobile radiotelephone for use in an area divided into small sections, each with its own short-range transmitter/receiver