casualty vs loss

casualty and loss both are nouns.

Word	Noun	Adjective	Verb	Adverb
casualty	Yes	No	No	No
loss	Yes	No	No	No

As nouns, loss is a hyponym of casualty; that is, loss is a word with a more specific, narrower meaning than casualty:

Other hyponyms of casualty include damage, equipment casualty, personnel casualty.

casualty (noun)	loss (noun)
a decrease of military personnel or equipment	the act of losing someone or something
an accident that causes someone to die	the disadvantage that results from losing something
someone injured or killed in an accident	military personnel lost by death or capture
someone injured or killed or captured or missing in a military engagement	the experience of losing a loved one
	euphemistic expressions for death
	the amount by which the cost of a business exceeds its revenue
	something that is lost
	gradual decline in amount or activity