-nə̇st noun
( -s )
: an advocate or promoter of union and especially of some form of unionism: as
a. usually capitalized : one loyal to the federal union of the United States during the Civil War
b. usually capitalized : a member of a former British political party advocating legislative union between Great Britain and Ireland
c. : an adherent or supporter of the labor union movement ; especially : an active member of a labor union
d. : an advocate of religious union and especially of the amalgamation of related Protestant sects