biodefense vs biodefence

biodefense and biodefence both are nouns.

Word	Noun	Adjective	Verb	Adverb
biodefense	Yes	No	No	No
biodefence	Yes	No	No	No

As nouns, biodefense and biodefence are synonyms defined as:

biodefense and biodefence: procedures involved in taking defensive measures against attacks using biological agents

Other synonyms of biodefense include biological defence, biological defense.

biodefense (noun)	biodefence (noun)
procedures involved in taking defensive measures against attacks using biological agents	procedures involved in taking defensive measures against attacks using biological agents