traffic vs drug traffic

traffic and drug traffic both are nouns.

Word	Noun	Adjective	Verb	Adverb
traffic	Yes	No	Yes	No
drug traffic	Yes	No	No	No

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

Other hyponyms of traffic include drug trafficking, narcotraffic, barratry, simony, slave trade, slave traffic.

traffic (noun)	drug traffic (noun)
buying and selling; especially illicit trade	traffic in illegal drugs
social or verbal interchange (usually followed by `with')
the amount of activity over a communication system during a given period of time
the aggregation of things (pedestrians or vehicles) coming and going in a particular locality during a specified period of time

traffic (verb)	drug traffic (verb)
deal illegally
trade or deal a commodity