execution vs shoot-down

execution and shoot-down both are nouns.

Word	Noun	Adjective	Verb	Adverb
execution	Yes	No	No	No
shoot-down	Yes	No	No	No

As nouns, shoot-down is a hyponym of execution; that is, shoot-down is a word with a more specific, narrower meaning than execution:

execution (noun)	shoot-down (noun)
putting a condemned person to death	murder by shooting someone down in cold blood
unlawful premeditated killing of a human being by a human being
the act of performing; of doing something successfully; using knowledge as distinguished from merely possessing it
the act of accomplishing some aim or executing some order
a routine court order that attempts to enforce the judgment that has been granted to a plaintiff by authorizing a sheriff to carry it out
(law) the completion of a legal instrument (such as a contract or deed) by signing it (and perhaps sealing and delivering it) so that it becomes legally binding and enforceable
(computer science) the process of carrying out an instruction by a computer