Smith's Bible Dictionary (1863)
(Heb. gao), anything convex or arched, as the boss of a shield, (Job 15:26) the eyebrows, (Leviticus 14:9) an eminent place. e. the hubs. In (Ezekiel 1:18) it is rendered twice “rings,” and margin “strakes,” an old word apparently used for the nave (hub) of a wheel and also more probably for the felloe or the tire, as making the streak or stroke upon the ground.