According to Parkhurst’s Greek and English Lexicon to the New Testament (London, 1845, p. 2), the Greek aʹbys·sos means “very or exceedingly deep.” According to Liddell and Scott’s Greek-English Lexicon (Oxford, 1968, p. 4), it means “unfathomable, boundless.”

Concerning the root meaning “unfathomable” as characteristic of “the abyss,” it is of interest to note the statement in Hastings’ Encyclopædia of Religion and Ethics (1913, Vol. I, p. 54), which, in commenting on Romans 10:6, 7, says: “The impression conveyed by St. Paul’s language is of the vastness of that realm, as of one that we should vainly attempt to explore.” Paul contrasts the inaccessibility of “heaven” and of the “abyss” with the accessibility of righteousness by faith. The use of the related word baʹthos made by Paul at Romans 11:33 illustrates this: “O the depth [baʹthos] of God’s riches and wisdom and knowledge! How unsearchable his judgments are and past tracing out his ways are!” (See also 1Co 2:10; Eph 3:18, 19.) So, in harmony with Romans 10:6, 7, the place that is represented by “the abyss” would also evidently imply being out of the reach of anyone but God or his appointed angel with “the key of the abyss.” (Re 20:1) Liddell and Scott’s Greek-English Lexicon (p. 4) gives as one of the meanings of the word aʹbys·sos “the infinite void.”