American Tract Society Bible Dictionary - Containing 2286 entries cross-referenced and cross-linked along with the images found in the original printed version. 1859

This encyclopedia, written in 1896 by Ashley S. Johnson, founder of Johnson Bible College, was and is designed for busy people who wish to increase their knowledge of the oracles of God. 1896

Baker's Evangelical Dictionary of Biblical Theology is a 753 entry dictionary of Theology.

A concise, compact Brethren dictionary with thousands of Biblical references. It lists and identifies all proper names, gives data on places and events of the scriptures, pronounciations, definitions and textual references.

A classic historical work of defining the Hebrew words of the Old Testament.

Buck's Theological Dictionary still contains some interesting material, especially when it comes to Religious Sects.

This is an old dictionary of Christianity in which a lot of unused (in modern speech) terms are defined. Over 1500 entries.

This Catholic dictionary is from 1990. It has thousands of short articles that seek to explain things from the Catholic point of view. Buyer beware! 

This is a concordance created by Alexander Cruden in 1737. 

This classic work is a comprehensive study on the life of Christ, including every reference to His life and teaching.