Morning star. (a)Any one of the planets (Venus, Jupiter, Mars, or Saturn) when it precedes the sun in rising, esp. Venus. Cf. Evening star, Evening. (b)Satan. See Lucifer. "Since he miscalled the morning star, Nor man nor fiend hath fallen so far." (c)A weapon consisting of a heavy ball set with spikes, either attached to a staff or suspended from one by a chain.