permit vs clearance

permit and clearance both are nouns.

Word	Noun	Adjective	Verb	Adverb
permit	Yes	No	Yes	No
clearance	Yes	No	No	No

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

Other hyponyms of permit include conge, congee, allowance, dispensation, toleration.

permit (noun)	clearance (noun)
the act of giving a formal (usually written) authorization	permission to proceed
large game fish; found in waters of the West Indies	the distance by which one thing clears another; the space between them
a legal document giving official permission to do something	vertical space available to allow easy passage under something

permit (verb)	clearance (verb)
consent to, give permission; permit
allow the presence of or allow (an activity) without opposing or prohibiting
make it possible through a specific action or lack of action for something to happen