whitethorn vs hawthorn

whitethorn and hawthorn both are nouns.

Word	Noun	Adjective	Verb	Adverb
whitethorn	Yes	No	No	No
hawthorn	Yes	No	No	No

As nouns, hawthorn is a hypernym of whitethorn; that is, hawthorn is a word with a broader meaning than whitethorn:

whitethorn: thorny Eurasian shrub of small tree having dense clusters of white to scarlet flowers followed by deep red berries; established as an escape in eastern North America
hawthorn: a spring-flowering shrub or small tree of the genus Crataegus

Other hypernyms of whitethorn include haw.

whitethorn (noun)	hawthorn (noun)
thorny Eurasian shrub of small tree having dense clusters of white to scarlet flowers followed by deep red berries; established as an escape in eastern North America	a spring-flowering shrub or small tree of the genus Crataegus