blackwash vs let on

blackwash is a noun but let on is not a noun.

Word	Noun	Adjective	Verb	Adverb
blackwash	Yes	No	Yes	No
let on	No	No	Yes	No

As verbs, let on is a hypernym of blackwash; that is, let on is a word with a broader meaning than blackwash:

blackwash: bring (information) out of concealment
let on: make known to the public information that was previously known only to a few people or that was meant to be kept a secret

Other hypernyms of blackwash include break, bring out, disclose, discover, divulge, expose, give away, let out, reveal, uncover, unwrap.

blackwash (noun)	let on (noun)
a wash that colors a surface black
a mixture of calomel and limewater that is used on syphilitic sores
an attack intended to ruin someone's reputation

blackwash (verb)	let on (verb)
color with blackwash	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
bring (information) out of concealment