big.tan is the proper name of a king's eunuch involved with Teresh in a plot against King Ahasuerus.

The term is used as a proper name for one of the king's eunuchs, named with Teresh in the account of an attempted attack on King Ahasuerus and Mordecai's report of it.

1. Proper name of a king's eunuch · dominant

   Both occurrences are tagged Noun · Proper and identify the same individual alongside Teresh. In Esther 2:21 the APB renders Bigthan and Teresh as eunuchs who guarded the threshold and sought to lay a hand on the king; in Esther 6:2 it renders Mordecai's report concerning those same two eunuchs.

   Esther 2:21Esther 6:2

In the Anselm Project Bible: The APB presents the term as "Bigthan" in both verses, each time alongside Teresh. This identifies the named figure in the verse rather than establishing a lexical English rendering.