red ink vs loss

red ink and loss both are nouns.

Word	Noun	Adjective	Verb	Adverb
red ink	Yes	No	No	No
loss	Yes	No	No	No

As nouns, red ink and loss are synonyms defined as:

red ink and loss: the amount by which the cost of a business exceeds its revenue

Other synonyms of red ink include red.

red ink (noun)	loss (noun)
the amount by which the cost of a business exceeds its revenue	the act of losing someone or something
	the disadvantage that results from losing something
	military personnel lost by death or capture
	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