betray vs let on

betray and let on both are verbs.

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

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

betray: reveal unintentionally
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 betray include break, bring out, disclose, discover, divulge, expose, give away, let out, reveal, uncover, unwrap.

betray (verb)	let on (verb)
give away information about somebody	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
reveal unintentionally
cause someone to believe an untruth
disappoint, prove undependable to; abandon, forsake
deliver to an enemy by treachery
be sexually unfaithful to one's partner in marriage