general practitioner vs medico

general practitioner and medico both are nouns.

Word	Noun	Adjective	Verb	Adverb
general practitioner	Yes	No	No	No
medico	Yes	No	No	No

As nouns, medico is a hypernym of general practitioner; that is, medico is a word with a broader meaning than general practitioner:

general practitioner: a physician who is not a specialist but treats all illnesses
medico: a licensed medical practitioner

Other hypernyms of general practitioner include doc, doctor, Dr., MD, physician.

general practitioner (noun)	medico (noun)
a physician who is not a specialist but treats all illnesses	a licensed medical practitioner
	a student in medical school