happy vs halcyon

happy is not a noun while halcyon is a noun.

Word	Noun	Adjective	Verb	Adverb
happy	No	Yes	No	No
halcyon	Yes	Yes	No	No

happy (noun)	halcyon (noun)
	a mythical bird said to breed at the time of the winter solstice in a nest floating on the sea and to have the power of calming the winds and waves

happy (adjective)	halcyon (adjective)
enjoying or showing or marked by joy or pleasure	marked by peace and prosperity
well expressed and to the point	idyllically calm and peaceful; suggesting happy tranquillity
marked by good fortune
eagerly disposed to act or to be of service