What is one who supports or sustains; especially, at a funeral, one of those who bear the copse, as distinguished from a bearer, or pallbearer, who helps to hold up the pall called?

underbearer — One who supports or sustains; especially, at a funeral, one of those who bear the copse, as distinguished from a bearer, or pallbearer, who helps to hold up the pall. (Webster's 1913.)