armour vs protective covering

armour and protective covering both are nouns.

Word	Noun	Adjective	Verb	Adverb
armour	Yes	No	Yes	No
protective covering	Yes	No	No	No

As nouns, protective covering is a hypernym of armour; that is, protective covering is a word with a broader meaning than armour:

As nouns, protective covering is a hypernym of armour; that is, protective covering is a word with a broader meaning than armour:

armour: protective covering made of metal and used in combat
protective covering: a covering that is intend to protect from damage or injury

Other hypernyms of armour include protection, protective cover.

armour (noun)	protective covering (noun)
tough more-or-less rigid protective covering of an animal or plant	the tough natural covering of some organisms
protective covering made of metal and used in combat	a covering that is intend to protect from damage or injury
a military unit consisting of armored fighting vehicles

armour (verb)	protective covering (verb)
equip with armor