thankful vs glad

thankful is not a noun while glad is a noun.

Word	Noun	Adjective	Verb	Adverb
thankful	No	Yes	No	No
glad	Yes	Yes	No	No

thankful (noun)	glad (noun)
	any of numerous plants of the genus Gladiolus native chiefly to tropical and South Africa having sword-shaped leaves and one-sided spikes of brightly colored funnel-shaped flowers; widely cultivated

thankful (adjective)	glad (adjective)
feeling or showing gratitude	showing or causing joy and pleasure; especially made happy
	cheerful and bright
	feeling happy appreciation
	eagerly disposed to act or to be of service