gum vs red gum

gum and red gum both are nouns.

Word	Noun	Adjective	Verb	Adverb
gum	Yes	No	Yes	No
red gum	Yes	No	No	No

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

gum: wood or lumber from any of various gum trees especially the sweet gum
red gum: reddish-brown wood and lumber from heartwood of the sweet gum tree used to make furniture

Other hyponyms of gum include hazelwood, satin walnut, sweet gum.

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

gum: any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying
red gum: reddish-brown dried gummy exudation from any of several trees of the genus Eucalyptus especially Eucalyptus camaldulensis

gum (noun)	red gum (noun)
the tissue (covered by mucous membrane) of the jaws that surrounds the bases of the teeth	red gum tree of Tasmania
a preparation (usually made of sweetened chicle) for chewing	very large red gum tree
any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum	a North American tree of the genus Liquidambar having prickly spherical fruit clusters and fragrant sap
wood or lumber from any of various gum trees especially the sweet gum	reddish-brown wood and lumber from heartwood of the sweet gum tree used to make furniture
any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying	reddish-brown dried gummy exudation from any of several trees of the genus Eucalyptus especially Eucalyptus camaldulensis
cement consisting of a sticky substance that is used as an adhesive

gum (verb)	red gum (verb)
exude or form gum
become sticky
grind with the gums; chew without teeth and with great difficulty
cover, fill, fix or smear with or as if with gum