say-so vs command

say-so and command both are nouns.

Word	Noun	Adjective	Verb	Adverb
say-so	Yes	No	No	No
command	Yes	No	Yes	No

As nouns, command is a hyponym of say-so; that is, command is a word with a more specific, narrower meaning than say-so:

Other hyponyms of say-so include power of appointment, carte blanche, imperium, lordship, muscle, sovereignty.

say-so (noun)	command (noun)
the power or right to give orders or make decisions	the power or authority to command
an authoritative declaration	availability for use
one chap's arbitrary assertion	great skillfulness and knowledge of some subject or activity
	an authoritative direction or instruction to do something
	(computer science) a line of code written as part of a computer program
	a military unit or region under the control of a single officer
	a position of highest authority

say-so (verb)	command (verb)
	make someone do something
	be in command of
	demand as one's due
	exercise authoritative control or power over
	look down on