military science vs discipline

military science and discipline both are nouns.

Word	Noun	Adjective	Verb	Adverb
military science	Yes	No	No	No
discipline	Yes	No	Yes	No

As nouns, discipline is a hypernym of military science; that is, discipline is a word with a broader meaning than military science:

Other hypernyms of military science include bailiwick, field, field of study, study, subject, subject area, subject field.

military science (noun)	discipline (noun)
the discipline dealing with the principles of warfare	training to improve strength or self-control
	the act of disciplining
	the trait of being well behaved
	a branch of knowledge
	a system of rules of conduct or method of practice

military science (verb)	discipline (verb)
	punish in order to gain control or enforce obedience
	develop (a child's or animal's) behavior by instruction and practice; especially to teach self-control