Concise Bible Dictionary:
The word is ψνχικός, “animal, sensuous,” in opposition to what is “spiritual.” It is translated “natural” (1 Cor. 2:14; 1 Cor. 15:44,46). To be sensual is to be led by the passions of man’s flesh: it is placed with “earthly” and “devilish” in James 3:15; and is contrasted with having the Holy Spirit in Jude 1:19.