freight vs freight rate

freight and freight rate both are nouns.

Word	Noun	Adjective	Verb	Adverb
freight	Yes	No	Yes	No
freight rate	Yes	No	No	No

As nouns, freight and freight rate are synonyms defined as:

freight and freight rate: the charge for transporting something by common carrier

Other synonyms of freight include freightage.

freight (noun)	freight rate (noun)
transporting goods commercially at rates cheaper than express rates	the charge for transporting something by common carrier
goods carried by a large vehicle
the charge for transporting something by common carrier

freight (verb)	freight rate (verb)
load with goods for transportation
transport commercially as cargo