FROM STRONG’S GREEK DICTIONARY (1890)

Strong’s Greek Dictionary (1890) — public domain, printed whole.

katachthonios καταχθόνιος — kat-akh-thon'-ee-os — from 2596 and chthon (the ground); subterranean, i.e. infernal (belonging to the world of departed spirits):--under the earth.

see GREEK for 2596