Mid 17th century; earliest use found in Thomas Blount (1618–1679), antiquary and lexicographer. From classical Latin lēgifer law-giving + -ous; compare -ferous.
Definition of legiferous in US English:
legiferous
adjectivelɪˈdʒɪf(ə)rəs
rare
That makes or lays down laws.
Origin
Mid 17th century; earliest use found in Thomas Blount (1618–1679), antiquary and lexicographer. From classical Latin lēgifer law-giving + -ous; compare -ferous.