slang vs lead astray

slang is a noun but lead astray is not a noun.

Word	Noun	Adjective	Verb	Adverb
slang	Yes	No	Yes	No
lead astray	No	No	Yes	No

As verbs, lead astray is a hypernym of slang; that is, lead astray is a word with a broader meaning than slang:

Other hypernyms of slang include betray, deceive.

slang (noun)	lead astray (noun)
a characteristic language of a particular group (as among thieves)
informal language consisting of words and expressions that are not considered appropriate for formal occasions; often vituperative or vulgar

slang (verb)	lead astray (verb)
abuse with coarse language	cause someone to believe an untruth
fool or hoax	lead someone in the wrong direction or give someone wrong directions
use slang or vulgar language	teach immoral behavior to