troll plate

Webster's Dictionary (GCIDE)

1.The act of moving round; routine; repetition. --Burke. [1913 Webster]

2.A song the parts of which are sung in succession; a catch; a round. [1913 Webster]

Thence the catch and troll, while "Laughter, holding both his sides," sheds tears to song and ballad pathetic on the woes of married life.— Prof. Wilson.[1913 Webster]

3.A trolley. [1913 Webster]

Troll plate (Mach.), a rotative disk with spiral ribs or grooves, by which several pieces, as the jaws of a chuck, can be brought together or spread radially. [1913 Webster]