special act vs legislative act

special act and legislative act both are nouns.

Word	Noun	Adjective	Verb	Adverb
special act	Yes	No	No	No
legislative act	Yes	No	No	No

As nouns, legislative act is a hypernym of special act; that is, legislative act is a word with a broader meaning than special act:

special act: a legislative act that applies only to a particular person or particular district
legislative act: an act passed by a legislative body

Other hypernyms of special act include statute.

special act (noun)	legislative act (noun)
a legislative act that applies only to a particular person or particular district	an act passed by a legislative body