ἐπιούσιον [2 verses](adj sg neut acc) "Daily" is epiousios, which may mean, "the appropriate," "sufficient for the coming," which first appears in Greek here. It could be an adjective from the verb epiousa, which means "to come on, to approach." It may also be from epi-eimi meaning literally "upon being" or "being upon." Some suggest is means "over being" or "above being" (from another meaning of epi) with the sense of meaning "supernatural" or "super-essential." Discussion about its possible meanings go back to the very early Christian writers. It is not the Greek word "daily," which is a form of the word "day.." -- (WW)  The word translated as "daily" is a mystery and one of the most interesting words in the Gospels. See this article for a complete historical discussion of this word. Its most likely and literal meaning is "existing upon."