tetrad vs Little Joe

tetrad and Little Joe both are nouns.

Word	Noun	Adjective	Verb	Adverb
tetrad	Yes	No	No	No
Little Joe	Yes	No	No	No

As nouns, tetrad and Little Joe are synonyms defined as:

tetrad and Little Joe: the cardinal number that is the sum of three and one

Other synonyms of tetrad include 4, four, foursome, IV, quadruplet, quartet, quatern, quaternary, quaternion, quaternity.

tetrad (noun)	Little Joe (noun)
the cardinal number that is the sum of three and one	the cardinal number that is the sum of three and one