tack vs thumbtack

tack and thumbtack both are nouns.

Word	Noun	Adjective	Verb	Adverb
tack	Yes	No	Yes	No
thumbtack	Yes	No	Yes	No

As nouns, thumbtack is a hyponym of tack; that is, thumbtack is a word with a more specific, narrower meaning than tack:

Other hyponyms of tack include carpet tack, drawing pin, pushpin, tintack.

As verbs, thumbtack is a hyponym of tack; that is, thumbtack is a word with a more specific, narrower meaning than tack:

tack (noun)	thumbtack (noun)
sailing a zigzag course	a tack for attaching papers to a bulletin board or drawing board
(nautical) the act of changing tack
a short nail with a sharp point and a large head
gear for a horse
(nautical) a line (rope or chain) that regulates the angle at which a sail is set in relation to the wind
the heading or position of a vessel relative to the trim of its sails

tack (verb)	thumbtack (verb)
reverse (a direction, attitude, or course of action)	fasten with thumbtacks
fasten with tacks
sew together loosely, with large stitches
fix to; attach
create by putting components or members together
turn into the wind