pervert vs lecher

pervert and lecher both are nouns.

Word	Noun	Adjective	Verb	Adverb
pervert	Yes	No	Yes	No
lecher	Yes	No	No	No

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

pervert: a person whose behavior deviates from what is acceptable especially in sexual behavior
lecher: man with strong sexual desires

pervert (noun)	lecher (noun)
a person whose behavior deviates from what is acceptable especially in sexual behavior	man with strong sexual desires

pervert (verb)	lecher (verb)
change the inherent purpose or function of something
practice sophistry; change the meaning of or be vague about in order to mislead or deceive
corrupt morally or by intemperance or sensuality