let alone vs leave behind

let alone and leave behind both are verbs.

Word	Noun	Adjective	Verb	Adverb
let alone	No	No	Yes	Yes
leave behind	No	No	Yes	No

As verbs, let alone and leave behind are synonyms defined as:

let alone and leave behind: leave unchanged or undisturbed or refrain from taking

Other synonyms of let alone include leave, leave alone.

let alone (verb)	leave behind (verb)
leave unchanged or undisturbed or refrain from taking	be survived by after one's death
	leave unchanged or undisturbed or refrain from taking
	depart and not take along

let alone (adverb)	leave behind (adverb)
much less