domino vs six-spot

domino and six-spot both are nouns.

Word	Noun	Adjective	Verb	Adverb
domino	Yes	No	No	No
six-spot	Yes	No	No	No

As nouns, six-spot is a hyponym of domino; that is, six-spot is a word with a more specific, narrower meaning than domino:

domino: a small rectangular block used in playing the game of dominoes; the face of each block has two equal areas that can bear 0 to 6 dots
six-spot: a playing card or domino or die whose upward face shows six pips

Other hyponyms of domino include five-spot, five, four-spot, four, one-spot, six.

domino (noun)	six-spot (noun)
a small rectangular block used in playing the game of dominoes; the face of each block has two equal areas that can bear 0 to 6 dots	a playing card or domino or die whose upward face shows six pips
a mask covering the upper part of the face but with holes for the eyes
a loose hooded cloak worn with a half mask as part of a masquerade costume