serial vs asynchronous

serial is a noun but asynchronous is not a noun.

Word	Noun	Adjective	Verb	Adverb
serial	Yes	Yes	No	No
asynchronous	No	Yes	No	No

serial (noun)	asynchronous (noun)
a serialized set of programs
a periodical that appears at scheduled times

serial (adjective)	asynchronous (adjective)
pertaining to or occurring in or producing a series	not synchronous; not occurring or existing at the same time or having the same period or phase
pertaining to or composed in serial technique	(digital communication) pertaining to a transmission technique that does not require a common clock between the communicating devices; timing signals are derived from special characters in the data stream itself
of or relating to the sequential performance of multiple operations
in regular succession without gaps