Buck’s Theological Dictionary still contains some interesting material, especially when it comes to Religious Sects.
American Tract Society Bible Dictionary – Containing 2286 entries cross-referenced and cross-linked along with the images found in the original printed version. 1859
Mounce Concise Greek-English Dictionary of the New Testament
Illustrated Bible Dictionary or Easton’s Bible Dictionary, is a reference work on topics related to the Christian Bible compiled by Matthew George Easton.
encinardemamre.com Bible Characters Dictionary is a dictionary of Bible characters, which is only people. 1187 entries
Ridling Bible Atlas is a 197 topics (about 180+ maps) that deal with Bible events and people from the Old Testament through the post New Testament age.
This Darby Bible Dictionary has 8400+ entries. Written by Brethren author John Darby, it has the Brethren point of view.
Thomas Brooks Complete Works is a 6 volume work on the works of Thomas Brooks.
Augustine Works of Saint Augustine Selected is a selection of Saint Augustine’s works, City of God (heaven) confessions, on Christian Doctrine, etc.
This dictionary Jackson Dictionary of Proper Names has just 23 chapters, one for each letter of the alphabet. In each one, it has all the proper names beginning with that letter, and its meaning.