graphology vs field of study

graphology and field of study both are nouns.

Word	Noun	Adjective	Verb	Adverb
graphology	Yes	No	No	No
field of study	Yes	No	No	No

As nouns, field of study is a hypernym of graphology; that is, field of study is a word with a broader meaning than graphology:

graphology: the study of handwriting (especially as an indicator of the writer's character or disposition)
field of study: a branch of knowledge

Other hypernyms of graphology include bailiwick, discipline, field, study, subject, subject area, subject field.

graphology (noun)	field of study (noun)
the study of handwriting (especially as an indicator of the writer's character or disposition)	a branch of knowledge