medium vs de-icer

medium and de-icer both are nouns.

Word	Noun	Adjective	Verb	Adverb
medium	Yes	Yes	No	No
de-icer	Yes	No	No	No

As nouns, de-icer is a hyponym of medium; that is, de-icer is a word with a more specific, narrower meaning than medium:

medium: an intervening substance through which something is achieved
de-icer: a substance used to melt ice; it can take a form of liquid or solid crystals.

Other hyponyms of medium include dissolvent, dissolver, dissolving agent, resolvent, solvent, ice melt, ice melter.

medium (noun)	de-icer (noun)
an occupation for which you are especially well suited	a substance used to melt ice; it can take a form of liquid or solid crystals.
an intervening substance through which signals can travel as a means for communication
a means or instrumentality for storing or communicating information
(usually plural) transmissions that are disseminated widely to the public
the surrounding environment
someone who serves as an intermediary between the living and the dead
a state that is intermediate between extremes; a middle position
(bacteriology) a nutrient substance (solid or liquid) that is used to cultivate micro-organisms
(biology) a substance in which specimens are preserved or displayed
a liquid with which pigment is mixed by a painter
an intervening substance through which something is achieved

medium (adjective)	de-icer (adjective)
(meat) cooked until there is just a little pink meat inside
around the middle of a scale of evaluation