Please can any one tell me what a warden is when mentioned in a defunct?

A while ago when I was searching for anything that will lead me to John Henry Cain, Union Mills around 1860 to 1866, I found these items. I had forgotten all about what I found as they were hiding in the bottom of my backpack!!

Defunct:
Jane Callow May 26th 1859
John Cain new warden
John cain Oct 1st 1861
John Cain 30 Sept 1863
All at Kirk braddan

And the last one;
Robert Cain 1863 K. Malew