ko'aḥ

This is the ordinary Hebrew word for strength understood as a stored-up capacity to do something. It is not the strength of a single muscle but the whole reserve of force a person, a people, or a thing can draw on, which is why the same word covers a man's bodily vigor, the productive power of farmland, a nation's military and economic might, and the limitless power of God.

Because it names a reserve, the word is felt most sharply when the reserve runs out. Again and again it appears in the form "there is no strength left," describing someone drained by grief, fasting, illness, or fear. The Bible plays on this: human strength is real but finite and quickly spent, while God gives strength to the faint and is himself never wearied.

The senses below are shades of this one idea, sorted by what kind of thing has the strength rather than by separate words. The thread that ties them is capacity held in reserve and put to use.

In the list of unclean swarming creatures in Leviticus 11, one name spelled the same as the word for strength denotes a small reptile, traditionally taken as a kind of large lizard or monitor lizard. It is unrelated in meaning to strength and is grouped with it only because Hebrew writes the two words with the same letters.

The word occurs just once in the Bible, in the catalog of forbidden creatures, so its exact species cannot be pinned down. Ancient and modern translations guess at it differently, which is why English Bibles render it variously.