The Hebrew word ru'ach literally means the wind and is derived from the parent root rach a prescribed path. The word rach is not found in the Biblical text but defined by the various child roots derived from it. The child roots derived from this parent root are arach, rachah and yarach. Arach is a traveler who follows a prescribed path from one place to another. Rachah is a millstone which goes round and round in the sense of following a prescribed path to crush grain into flour. Yarach is the root of yere'ach meaning the moon which follows a prescribed path in the night sky. The child root ru'ach is literally the wind that follows a prescribed path each season. By extension ru'ach means the wind of a man or what is usually translated as spirit. A man's wind is not just a spiritual entity within a man but is understood by the Ancient Hebrews as his character.
AHLB# 1445-j (N)