Boyd’s Bible Dictionary:
A word which, with clean, was applied to personal and ceremonial conditions, as well as to the edibility of animals
The division of animals into clean and unclean existed before the Flood (Gen. 7:2). Uncleanness and the processes of purification are particularly described (Lev. 11-15; Num. 19). Unclean animals are specially mentioned (Lev. 11:9-31; Deut. 14:3-20).
Concise Bible Dictionary:
See ANIMALS
Strong’s Dictionary of Greek Words:
Transliteration:
akathartos
Meaning:
from 1 (as a negative particle) and a presumed derivative of 2508 (meaning cleansed); impure (ceremonially, morally (lewd) or specially, (demonic))