attacker vs night rider

attacker and night rider both are nouns.

Word	Noun	Adjective	Verb	Adverb
attacker	Yes	No	No	No
night rider	Yes	No	No	No

As nouns, night rider is a hyponym of attacker; that is, night rider is a word with a more specific, narrower meaning than attacker:

attacker: someone who attacks
night rider: member of a secret mounted band in United States South after the American Civil War; committed acts of intimidation and revenge

attacker (noun)	night rider (noun)
someone who attacks	member of a secret mounted band in United States South after the American Civil War; committed acts of intimidation and revenge